地基勘察与施工中英文对照外文翻译文献

专业资料英文原文：Building construction concrete crack ofprevention and processingAbstractThe crack problem of concrete is a widespread existence but againdifficult in solve of engineering actual problem, this text carried ona study analysis to a little bit familiar crack problem in the concreteengineering,and aim at concrete the circumstance put forward some prevention, processing measure.Keyword: Concrete crack prevention processingForewordConcrete's is 1 kind is anticipate by the freestone bone, cement,water and other mixture but formation of the in addition material ofquality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole,spirit cave and tiny crack, is exactly because these beginning start blemish ofexistence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use functionnot a creation to endanger.But after the concrete be subjected to lotus carry,difference in temperature etc.function,tiny crack wouldcontinuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that theconcrete often say in the engineering.Concrete building and Gou piece usually all take sewer to make of,because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concretematerial of loading ability, durable and anti- Shen ability, influencebuilding of external appearance,service life,severity will threat arrive people's life and property safety. A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that. Modern age science research with a great deal of of theconcrete engineering practice certificate, in the concrete engineeringcrack problem is ineluctable, also acceptable in certainly of the scopejust need to adopt valid of measure will it endanger degree control atcertain of scope inside. The reinforced concrete norm is also explicitprovision: Some structure at place of dissimilarity under the conditionallow existence certain the crack of width. But at under constructionshould as far as possible adopt a valid measure control crack creation,make the structure don't appear crack possibly or as far as possibledecrease crack of amount and width,particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus.Concrete crack creation of the reason be a lot of and have alreadytransformed to cause of crack: Such as temperature variety,constringency, inflation, the asymmetry sink to sink etc. reason cause of crack; Haveoutside carry the crack that the function cause; Protected environment not appropriate the crack etc. caused with chemical e ffect.Want differentiation to treat in the actual engineering, workout a problemaccording to the actual circumstance.In the concrete engineering the familiar crack and the prevention1.Stem Suo crack and preventionStem the Suo crack much appear after the concrete protect be overof a period of time or concrete sprinkle to build to complete behind ofaround a week. In the cement syrup humidity of evaporate would creationstem Suo, and this kind of constringency is can't negative.Stem Suo crack of the creation be main is because of concrete inside outside humidityevaporate degree dissimilarity but cause to transform dissimilarity ofresult: The concrete is subjected to exterior condition of influence,surface humidity loss lead quick, transform bigger,inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suotransform to be subjected to concrete inner part control, creation morebig pull should dint but creation crack. The relative humidity is morelow, cement syrup body stem Suo more big,stem the Suo crack be more easy creation. Stem the Suo crack is much surface parallel lines form or thenet shallow thin crack,mm, the flat surfacepart much see in the big physical volume concrete and follow it more inthinner beam plank short to distribute.Stem Suo crack usually the anti-Shen of influence concrete,cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the waterpressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with waterash of the concrete ratio,the dosage of the composition,cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant.Main prevention measure: While being to choose to use the constringency quantity smaller cement, general low hot water mire andpowder ash from stove cement in the adoption,lower the dosage of cement. Two is a concrete of stem the Suo be subjected to water ash ratio ofinfluence more big, water ash ratio more big, stem Suo more big, so inthe concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water.Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantityabsolute can't big in match ratio design give settle of use water quantity. Four is the earlier period which strengthen concrete to protect, andappropriate extension protect of concrete time.Winter construction want to be appropriate extension concrete heat preservation to overlay time,and Tu2 Shua protect to protect.Five is a constitution the accommodation is in the concrete structure of the constringency sew.2.The Su constringency crack and preventionSu constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack'smuch presenting in the center breadth, both ends be in the center thinand the length be different, with each other not coherent appearance.Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3m, breadth1-5mm. It creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning verysmall, perhaps concrete just eventually Ning but strength very hour, besubjected to heat or compare strong wind dint of influence,the concrete surface lose water to lead quick, result in in the capillary creationbigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again can'tresist its constringency,therefore creation cracked.The influence concrete Su constringency open the main factor of crack to have water ash ratio,concrete of condense time,environment temperature,wind velocity, relative humidity...etc..Main prevention measure: One is choose to use stem the Suo valuesmaller higher Huo sour salt of the earlier period strength or commontheHuo sour brine mire. Two is strict the control water ash ratio, the Chanadd to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of dosage. Three is to sprinkle before building concrete, water basic level and template evento soak through. Four is in time to overlay the perhaps damp grass matof the plastics thin film, hemp slice etc., keep concrete eventuallybefore the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface. Five is in the heat and strong windthe weather to want to establish to hide sun and block breeze facilities, protect in time.3.Sink to sink crack and preventionThe creation which sink to sink crack is because of the structurefoundation soil quality not and evenly,loose soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to declinewith the result that; Perhaps because of template just degree shortage,the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the template prop up at jellysoil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation crack.This kind crack many is deep enter or pierce through sex crack, it alignment have somethingto do with sinking to sink a circumstance, general follow with groundperpendicular or present 30°s-45 °Cape direction development, biggersink to sink crack, usually have certain of wrong, crack width usuallywith sink to decline quantity direct proportion relation. Crack widthunder the influence of temperature variety smaller.The foundation after transform stability sink to sink crack also basic tend in stability.Main prevention measure: One is rightness loose soft soil, returnto fill soil foundation a construction at the upper part structure front should carry on necessity of Hang solid with reinforce.Twois the strength that assurance template is enough and just degree, and prop up firm,and makethe foundation be subjected to dint even. Three is keep concrete from sprinkle infusing the foundation in the process is soak by water. Fouris time that template tore down to can't be too early,and want to notice to dismantle a mold order of sequence. Five is at jelly soil top take toestablish template to notice to adopt certain of prevention measure.4.Temperature crack and preventionTemperature crack muchthe occurrence is in big surface or differencein temperature variety of the physical volume concrete compare the earth area of the concrete structure. Concrete after sprinkling to build, inthe hardening the process, cement water turn a creation a great deal ofof water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, eachsign square the rice concrete will release a calories of 17500-27500 kJand make concrete internal thus the temperature rise to reach to 70℃or so even higher)Because the physical volume of concrete be more big,a great deal of of water turn hot accumulate at the concrete inner partbut not easy send forth, cause inner part the temperature hoick,but the concrete surface spread hot more quick, so formation inside outside ofbigger difference in temperature, the bigger difference in temperatureresult in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull shoulddint.When pull should dint exceed the anti- of concrete pull strengthextreme limit,concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc.,will cause concrete surface the temperature sharply descend,but creation constringency, surface constringency of the concrete be subjected toinner part concrete of control,creation very big of pull should dint but creation crack, this kind of crack usually just in more shallow scope of the concrete surface creation.The alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;The size biggerstructure of the beamplank length, the crack run parallel with short side more;Thorough with pierce through sex of temperature crack general andshort side direction parallelism or close parallelism, crack along longside cent the segment appear, in the c enter width thesize be different, be subjected to temperature variety influence moreobvious,winter compare breadth,summer more narrow.The concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin,but cold Suo crack of thick thin variety not too obvious.The emergence of the this kind crack will cause the rusteclipse of reinforcing bar,the carbonization of concrete,the anti-jelly which lower concrete melt, anti- tired and anti- Shen ability etc..Main prevention measure:One is as far as possible choose to use lowhot or medium hot water mire, like mineral residue cement,powder ash from stove cement...etc..Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450 kg/m 3 following.Three is to lowerwater ash ratio, water ash of the general concrete ratio control below0.6.Four is improvement the bone anticipate class to go together with,the Chan add powder ash from stove or efficiently reduce water etc. tocome to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lower sprinkle ofconcrete to build temperature.Six is the in addition that the Chan adda have of fixed amount to reduce water and increase Su, slow Ning etc.function in the concrete, improvement the concrete mix to match a thingof mobility, protect water, lower water to turn hot, postpone hot Fengof emergence time.Seven is the heat season sprinkle to build can theadoption take to establish to hide sun plank etc. assistance measurecontrol concrete of WenSheng, lower to sprinkle temperature of build the is the temperature of big physical volume concrete should the dint relate to structure size, concrete structure size more big,temperature should dint more big,so want reasonable arrangement construction work preface, layering, cent the piece sprinkle to build,for the convenience of in spread hot,let is at great inner part constitution of the physical volume concrete cool off piping, coldwater perhaps cold air cool off,let up concrete of inside outside difference in is the supervision which strengthenis to reserve temperature constringency to sew.12 is to let up to control, sprinkle proper before building concrete in the Ji rock and old concrete top build a 5 mm or so sand mat a layer or usage asphalt etc. materialTu2 Shua.13 is to strengthen concrete to protect, the concrete aftersprinkle build use moist grass Lian in time, hemp slice's etc. overlay,and attention sprinkle water to protect, appropriate extension protecttime,assurance the concrete surface be slow-moving cool the cold season,concrete surface should constitution heat preservation measure, in order to prevent cold wave assault.14 is the allocation be a littleamount in the concrete of reinforcing bar perhaps add fiber materialconcrete of temperature crack control at certain of scope inside.5.Crack and prevention that the chemical reaction causeAlkali bone's anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the r einforced concrete structure of because of chemical reaction but cause of crack.The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open crack.In thiskind of crack general emergence concrete structure usage period, onceappear very difficult remediable, so should at under construction adoptvalid the measure carry on prevention.Main of prevention measure:Whilebeing to choose to anticipate with the alkali activity small freestonebone.Two is the in addition which choose to use low lye mire with low alkaliis the Chan which choose to use accommodation with anticipate to repress an alkali bone to anticipate reaction.Because the concrete sprinkle to build, flap Dao bad perhaps is areinforcing bar protection layer thinner, the harmful material get intoconcrete to make reinforcing bar creation rust eclipse, the reinforcingbar physical volume of the rust eclipse inflation, cause concrete bulgecrack,the crack of this kind type much is a crack lengthways,follow the position of reinforcing bar of prevent measure from have:One is assurance reinforcing bar protection the thickness of thelayer.Two is a concrete class to go together with to want good.Three isa concrete to sprinkle to note and flap Dao airtight solid.Four is areinforcing bar surface layer Tu2 Shua antisepsis coating.Crack processingThe emergence of the crack not only would influence structure of whole with just degree,return will cause the rust eclipse of reinforcing bar, acceleration concrete of carbonization,lower durable and anti-of concrete tired, anti- Shen ability.Therefore according to the propertyof crack and concrete circumstance we want differentiation to treat, intime processing, with assurance building of safety usage.The repair measure of the concrete crack is main to have the following somemethod:Surface repair method, infuse syrup,the Qian sew method, the structure reinforce a method, concrete displacement method, electricity chemistry protection method and imitate to living from heal method.Surface repair the method be a kind of simple, familiar of repairmethod, it main be applicable to stability and to structure loading theability don't have the surface crack of influence and deep enter crackprocessing measure that is usually is a surface in crack daubery cement syrup, the wreath oxygen gum mire or at concrete surfaceTu2 Shua paint,asphalt etc.antisepsis material,at protection of in the meantime for keeping concrete from continue under the influence of various function to open crack, usually can adoption the surface in crack glueto stick glass fiber cloth etc. measure.1, infuse syrup, the Qian sew methodInfuse a syrup method main the concrete crack been applicable to have influence or have already defend Shen request to the structure whole ofrepair, it is make use of pressure equipments gumknot the material press into the crack of concrete, gum knot the material harden behind andconcrete formation one be whole, thus reinforce of purpose.The in common use gumknot material has the cement the syrup, epoxy, A Ji C Xi sour ester and gather ammonia ester to equalize to learn material.The Qian sew a method is that the crack be a kind of most in commonuse method in, it usually is follow the crack dig slot, the Qian fill Suin the slot or rigid water material with attain closing crack of purpose.The in commonuse Su material has PVCgummire, plastics ointment, the D Ji rubber etc.;In common use rigid water material is the polymercement sand syrup.2, the structure reinforce a methodWhenthe crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure.The structure reinforce medium in commonuse main havethe following a few method:The piece of enlargement concrete structurein every aspect accumulate, outside the Cape department of the Gou piece pack type steel, adoption prepare should the dint method reinforce,glueto stick steel plate to reinforce, increase to establish fulcrum toreinforce and jet the concrete compensation reinforce.3, concrete displacement methodConcrete displacement method is processing severity damage concrete ofa kind of valid method, this method be first will damage of the concretepick and get rid of, then again displacement go into new of concrete orother in common use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup.4, the electricity chemistry protection methodThe electricity chemistry antisepsis is to makeuse of infliction electric field in lie the quality of electricity chemical effect,change concrete or reinforced concrete the environment appearance of the place, the bluntness turn reinforcing bar to attain the purpose ofprotection method, chlorine salt's withdrawing a method, alkalescence to recover a method is a chemistry protection method in three kinds of in common use but valid method.The advantage of thiskind of method is a protection method under the influence of environment factor smaller,apply reinforcing bar,concrete of long-term antisepsis, since can used for crack structure already can also used for new set upstructure.5, imitate to living from legal moreImitate to living from heal the method be a kind of new crack treatment,its mimicry living creature organization secrete a certain material towards suffering wound part auto,but makethe wound part heal of function, join some and special composition(such as contain to glue knot of theliquid Xin fiber or capsule)in the concrete of the tradition the composition,at concrete inner part formation the intelligence type imitate to living from heal nerve network system,be the concrete appear crack secrete a parts of liquid Xin fiber can make the crack re- heal.ConclusionThe crack is widespread in the concrete structure existence of a kindof phenomenon, it of emergence not only will lower the anti- Shen ofbuilding ability, influence building of usage function, and will causethe rust eclipse of reinforcing bar, the carbonization of concrete,lowerthe durable of material, influence building of loading ability, so wantto carry on to the concrete crack earnest research, differentiation treat, adoption reasonable of the method carry on processing, and at underconstruction adopt various valid of prevention measure to preventioncrack of emergence and development, assurance building and Gou piecesafety, stability work.From《CANADIAN JOURNAL OF CIVIL ENGINEERING》中文原文：建筑施工混凝土裂缝的预防与办理混凝土的裂缝问题是一个宽泛存在而又难于解决的工程实责问题，本文对混凝土工程中常有的一些裂缝问题进行了商议解析，并针对详尽情况提出了一些预防、办理措施。

施工测量英文文献Construction Surveying is a critical component of civil engineering projects, ensuring the accuracy and precision of the construction process. It involves the application of various surveying techniques to determine the exact positions of points, lines, and contours on the Earth's surface. This process is essential for the proper planning, design, and execution of construction projects.The primary objective of construction surveying is to establish a reliable and accurate control network that serves as a reference for all subsequent construction activities. This includes the layout of roads, bridges, buildings, and other structures. Surveyors use a variety of instruments such as total stations, GPS receivers, and digital levels to collect the necessary data.One of the initial steps in construction surveying is the establishment of a horizontal and vertical control network. This involves setting up a series of benchmark points that are used to orient and align the construction elements. The control network serves as a reference for all subsequent measurements, ensuring that the construction is carried out according to the design specifications.Once the control network is established, the surveyors proceed to stake out the exact positions of the structures to be built. This involves the use of precise measurements tolocate the corners of buildings, the centerlines of roads, and the positions of other critical construction elements. The stakes are typically marked with flags, paint, or other visible indicators to guide the construction crews.As construction progresses, surveyors continue to monitor the work to ensure that it is being carried out correctly. This may involve checking the alignment of walls, the elevation of floors, and the position of other structural elements. Any discrepancies are identified and corrected to ensure that the final structure meets the design specifications.Modern construction surveying also incorporates the use of advanced technologies such as Building Information Modeling (BIM) and Geographic Information Systems (GIS). These tools allow surveyors to integrate their data with other aspects of the construction process, providing a more comprehensive and integrated approach to project management.In conclusion, construction surveying is a vital aspect of the construction industry, providing the necessary data and control for the accurate and efficient execution of construction projects. With the ongoing advancements in technology, the role of surveyors is becoming increasingly important in ensuring the success of these projects.。

外文翻译土木工程英文文献文献翻译外文原文Stage of construction cost controlConstruction enterprises in engineering construction of a construction project cost management is the foundation of the enterprise survival and the development and the core of the construction stage does well the cost control to achieve the purpose of increasing earnings is the project activities more important link, this paper will carry on the elaboration to this question, so that in enterprise production and management play a directive role.So in the project construction cost control what are the content? The author through 10 years of work experience, and analysis has the following aspects:contract aspects: according to construction drawing, contracting contract as the basis, according to the requirements of the contract project, quality, progress index, compiled in detail the construction organization design, this as the basis of cost plan. The project is in the contract and the existence of the change of component project,report to. As far as possible increases the project income. Use contract rights granted reasonable increase income and reduce expenditure.technical aspects: first of all, according to the actual situationof construction site, scientific planning of the construction site layout, to reduce the waste and save money to create conditions; Basedon its technical superiority, fully mobilize the enthusiasm of management personnel, and carry out the mention reasonable suggestion activities, the expansion of nearly may cost control of scope and depth.quality and security; In strict accordance with the engineering technical specifications and rules of safe operation management, reduce and eliminate quality and safety accidents, make all sorts of loss is reduced to the minimum.machinery management: according to the requirements of project scientific, reasonable selection of machinery, give full play to the mechanical performance; Be reasonable arrangement construction in order to improve the utilization rate of the machinery, reduce machine fee cost; Regular maintenance machinery, improve the integrity rate of the machinery, provide guarantee for the whole progress. For the rent mustbe the mechanical equipment, to improve market research touch bottom the material aspects: material purchasing should be abided by "quality, low price and short distance of the principle of" approach to correct materials measurement, serious acceptance, the maximum limit reduced purchasingmanagement in the process of consumption. According to the construction schedule science organization the use of material plan, avoid downtime should phenomenon; Material drawing shall be strictly controlled, regular inventory, grasps the actual1consumption and the progress of the projects contrast data; For inthe recovery turnover materials, sorting, completed with timely and exits, like this is advantageous to the turnover use and reduce thelease fees, and reduce the cost.and administrative management: first to streamline management institutions, avoid overstaffing, reduce unnecessary salary expenses; Control business expenses and so on each unproductive spending Numbers. The administrative office of the materials with property, all on thecard USES, prevent damage and loss,and financial aspects: the financial department is an important part of the cost control, mainly through the spending review all the expenses, balance scheduling funds and establishing various auxiliary records and hard working with all department cost implementation method such as the inspection and supervision, and the engineering cost analysis of all-round and provide feedback to decision-making departments, in order to take effective measures to correct the deviation of the project cost.More from seven aspects of simple described the content of the responsibility cost management, so in the construction of how tospecific implementation, which we need to master the dynamic control of the construction project cost.In short, the construction project cost control is a complicated system engineering. Construction project cost control, the need for flexible use of, the actual operation should adjust measures to local conditions, different project size, different construction enterprise,different management system have differences, but no matter how construction enterprise to manage production is the consumption of human resources, material resources and cost, guidance, supervision and regulation and restrictions2译文施工阶段成本控制建筑施工企业在工程建设中实行施工项目成本管理是企业生存和发展的基础和核心，在施工阶段搞好成本控制，达到增收节支的目的是项目经营活动中更为重要的环节，本文将对这一问题进行论述，以便在企业的生产经营中起指导作用。

Civil engineeringCivil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like bridges, roads, canals, dams, and buildings.[1][2][3] Civil engineering is the oldest engineering discipline after military engineering,[4] and it was defined to distinguish non-military engineering from military engineering.[5] It is traditionally broken into several sub-disciplines including environmental engineering, geotechnical engineering, structural engineering, transportation engineering, municipal or urban engineering, water resources engineering, materials engineering, coastal engineering,[4] surveying, and construction engineering.[6] Civil engineering takes place on all levels: in the public sector from municipal through to national governments, and in the private sector from individual homeowners through to international companies.History of the civil engineering professionSee also: History of structural engineeringEngineering has been an aspect of life since the beginnings of human existence. The earliest practices of Civil engineering may have commenced between 4000 and 2000 BC in Ancient Egypt and Mesopotamia (Ancient Iraq) when humans started to abandon a nomadic existence, thus causing a need for the construction of shelter. During this time, transportation became increasingly important leading to the development of the wheel and sailing.Until modern times there was no clear distinction between civil engineering and architecture, and the term engineer and architect were mainly geographical variations referring to the same person, often used interchangeably.[7]The construction of Pyramids in Egypt (circa 2700-2500 BC) might be considered the first instances of large structure constructions. Other ancient historic civil engineering constructions include the Parthenon by Iktinos in Ancient Greece (447-438 BC), theAppian Way by Roman engineers (c. 312 BC), the Great Wall of China by General Meng T'ien under orders from Ch'in Emperor Shih Huang Ti (c. 220 BC)[6] and the stupas constructed in ancient Sri Lanka like the Jetavanaramaya and the extensive irrigation works in Anuradhapura. The Romans developed civil structures throughout their empire, including especially aqueducts, insulae, harbours, bridges, dams and roads.In the 18th century, the term civil engineering was coined to incorporate all things civilian as opposed to military engineering.[5]The first self-proclaimed civil engineer was John Smeaton who constructed the Eddystone Lighthouse.[4][6]In 1771 Smeaton and some of his colleagues formed the Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner. Though there was evidence of some technical meetings, it was little more than a social society.In 1818 the Institution of Civil Engineers was founded in London, and in 1820 the eminent engineer Thomas Telford became its first president. The institution received a Royal Charter in 1828, formally recognising civil engineering as a profession. Its charter defined civil engineering as:the art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states, both for external and internal trade, as applied in the construction of roads, bridges, aqueducts, canals, river navigation and docks for internal intercourse and exchange, and in the construction of ports, harbours, moles, breakwaters and lighthouses, and in the art of navigation by artificial power for the purposes of commerce, and in the construction and application of machinery, and in the drainage of cities and towns.[8] The first private college to teach Civil Engineering in the United States was Norwich University founded in 1819 by Captain Alden Partridge.[9] The first degree in Civil Engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835.[10] The first such degree to be awarded to a woman was granted by Cornell University to Nora Stanton Blatchin 1905.History of civil engineeringCivil engineering is the application of physical and scientific principles, and its history is intricately linked to advances in understanding of physics and mathematics throughout history. Because civil engineering is a wide ranging profession, including several separate specialized sub-disciplines, its history is linked to knowledge of structures, materials science, geography, geology, soils, hydrology, environment, mechanics and other fields.Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stone masons and carpenters, rising to the role of master builder. Knowledge was retained in guilds and seldom supplanted by advances. Structures, roads and infrastructure that existed were repetitive, and increases in scale were incremental.[12]One of the earliest examples of a scientific approach to physical and mathematical problems applicable to civil engineering is the work of Archimedes in the 3rd century BC, including Archimedes Principle, which underpins our understanding of buoyancy, and practical solutions such as Archimedes' screw. Brahmagupta, an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, for excavation (volume) computations.[13]Civil engineers typically possess an academic degree with a major in civil engineering. The length of study for such a degree is usually three to five years and the completed degree is usually designated as a Bachelor of Engineering, though some universities designate the degree as a Bachelor of Science. The degree generally includes units covering physics, mathematics, project management, design and specific topics in civil engineering. Initially such topics cover most, if not all, of thesub-disciplines of civil engineering. Students then choose to specialize in one or more sub-disciplines towards the end of the degree.[14]While anUndergraduate (BEng/BSc) Degree will normally provide successful students with industry accredited qualification, some universities offer postgraduate engineering awards (MEng/MSc) which allow students to further specialize in their particular area of interest within engineering.[15]In most countries, a Bachelor's degree in engineering represents the first step towards professional certification and the degree program itself is certified by a professional body. After completing a certified degree program the engineer must satisfy a range of requirements (including work experience and exam requirements) before being certified. Once certified, the engineer is designated the title of Professional Engineer (in the United States, Canada and South Africa), Chartered Engineer (in most Commonwealth countries), Chartered Professional Engineer (in Australia and New Zealand), or European Engineer (in much of the European Union). There are international engineering agreements between relevant professional bodies which are designed to allow engineers to practice across international borders.The advantages of certification vary depending upon location. For example, in the United States and Canada "only a licensed engineer may prepare, sign and seal, and submit engineering plans and drawings to a public authority for approval, or seal engineering work for public and private clients.".[16]This requirement is enforced by state and provincial legislation such as Quebec's Engineers Act.[17]In other countries, no such legislation exists. In Australia, state licensing of engineers is limited to the state of Queensland. Practically all certifying bodies maintain a code of ethics that they expect all members to abide by or risk expulsion.[18] In this way, these organizations play an important role in maintaining ethical standards for the profession. Even in jurisdictions where certification has little or no legal bearing on work, engineers are subject to contract law. In cases where an engineer's work fails he or she may be subject to the tort of negligence and, in extreme cases, thecharge of criminal negligence.[citation needed] An engineer's work must also comply with numerous other rules and regulations such as building codes and legislation pertaining to environmental law.CareersThere is no one typical career path for civil engineers. Most people who graduate with civil engineering degrees start with jobs that require a low level of responsibility, and as the new engineers prove their competence, they are trusted with tasks that have larger consequences and require a higher level of responsibility. However, within each branch of civil engineering career path options vary. In some fields and firms, entry-level engineers are put to work primarily monitoring construction in the field, serving as the "eyes and ears" of senior design engineers; while in other areas, entry-level engineers perform the more routine tasks of analysis or design and interpretation. Experienced engineers generally do more complex analysis or design work, or management of more complex design projects, or management of other engineers, or into specialized consulting, including forensic engineering.In general, civil engineering is concerned with the overall interface of human created fixed projects with the greater world. General civil engineers work closely with surveyors and specialized civil engineers to fit and serve fixed projects within their given site, community and terrain by designing grading, drainage, pavement, water supply, sewer service, electric and communications supply, and land divisions. General engineers spend much of their time visiting project sites, developing community consensus, and preparing construction plans. General civil engineering is also referred to as site engineering, a branch of civil engineering that primarily focuses on converting a tract of land from one usage to another. Civil engineers typically apply the principles of geotechnical engineering, structural engineering, environmental engineering, transportation engineering and construction engineering toresidential, commercial, industrial and public works projects of all sizes and levels of construction翻译：土木工程土木工程是一个专业的工程学科，包括设计，施工和维护与环境的改造，涉及了像桥梁，道路，河渠，堤坝和建筑物工程交易土木工程是最古老的军事工程后，工程学科，它被定义为区分军事工程非军事工程的学科它传统分解成若干子学科包括环境工程，岩土工程，结构工程，交通工程，市或城市工程，水资源工程，材料工程，海岸工程，勘测和施工工程等土木工程的范围涉及所有层次：从市政府到国家，从私人部门到国际公司。

英文原文：Building construction concrete crack ofprevention and processingAbstractThe crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure.Keyword: Concrete crack prevention processingForewordConcrete's is 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material. Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality. The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger. But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering.Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and anti- Shen ability, influence building of external appearance, service life, severity will threat arrive people's life and property safety. A lot of all of crash of engineerings is because of the unsteady development of the crack with the resultthat. Modern age science research with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside. The reinforced concrete norm is also explicit provision: Some structure at place of dissimilarity under the condition allow existence certain the crack of width. But at under construction should as far as possible adopt a valid measure control crack creation, make the structure don't appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus.Concrete crack creation of the reason be a lot of and have already transformed to cause of crack: Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reason cause of crack; Have outside carry the crack that the function cause; Protected environment not appropriate the crack etc. caused with chemical effect. Want differentiation to treat in the actual engineering, workout a problem according to the actual circumstance.In the concrete engineering the familiar crack and the prevention1.Stem Suo crack and preventionStem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week. In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't negative. Stem Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result: The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pull should dint but creation crack. The relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy creation. Stem the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0.2 mm,the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short to distribute. Stem Suo crack usually the anti- Shen of influence concrete, cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant.Main prevention measure: While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement. Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water. Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can't big in match ratio design give settle of use water quantity. Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time. Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect. Five is a constitution the accommodation is in the concrete structure of the constringency sew.2.The Su constringency crack and preventionSu constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency. The Su constringency crack is general at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the center thin and the length be different, with each other not coherent appearance. Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 mm. It creation of main reason is: The concrete is eventually almost having no strength or strength before the Ning very small, perhapsconcrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again can't resist its constringency, therefore creation cracked. The influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature, wind velocity, relative humidity...etc..Main prevention measure: One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire. Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of dosage. Three is to sprinkle before building concrete, water basic level and template even to soak through. Four is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface. Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time.3.Sink to sink crack and preventionThe creation which sink to sink crack is because of the structure foundation soil quality not and evenly, loose soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to decline with the result that; Perhaps because of template just degree shortage, the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the template prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation crack. This kind crack many is deep enter or pierce through sex crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or present 30 °s-45 °Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion relation. Crack width under the influence of temperature variety smaller. The foundation aftertransform stability sink to sink crack also basic tend in stability.Main prevention measure: One is rightness loose soft soil, return to fill soil foundation a construction at the upper part structure front should carry on necessity of Hang solid with reinforce. Two is the strength that assurance template is enough and just degree, and prop up firm, and make the foundation be subjected to dint even. Three is keep concrete from sprinkle infusing the foundation in the process is soak by water. Four is time that template tore down to can't be too early, and want to notice to dismantle a mold order of sequence. Five is at jelly soil top take to establish template to notice to adopt certain of prevention measure.4.Temperature crack and preventionTemperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete compare the earth area of the concrete structure. Concrete after sprinkling to build, in the hardening the process, cement water turn a creation a great deal of of water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, each sign square the rice concrete will release a calories of 17500-27500 kJ and make concrete internal thus the temperature rise to reach to 70 ℃or so even higher)Because the physical volume of concrete be more big, a great deal of of water turn hot accumulate at the concrete inner part but not easy send forth, cause inner part the temperature hoick, but the concrete surface spread hot more quick, so formation inside outside of bigger difference in temperature, the bigger difference in temperature result in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull should dint.When pull should dint exceed the anti- of concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction period.In the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc., will cause concrete surface the temperature sharply descend, but creation constringency, surface constringency of the concrete be subjected to inner part concrete of control, creation very big of pull should dint but creation crack, this kind of crack usually just in more shallow scope ofthe concrete surface creation.The alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;The size bigger structure of the beam plank length, the crack run parallel with short side more;Thorough with pierce through sex of temperature crack general and short side direction parallelism or close parallelism, crack along long side cent the segment appear, in the center more airtight.Crack width the size be different, be subjected to temperature variety influence more obvious, winter compare breadth, summer more narrow.The concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin, but cold Suo crack of thick thin variety not too obvious.The emergence of the this kind crack will cause the rust eclipse of reinforcing bar, the carbonization of concrete, the anti- jelly which lower concrete melt, anti- tired and anti- Shen ability etc..Main prevention measure:One is as far as possible choose to use low hot or medium hot water mire, like mineral residue cement, powder ash from stove cement...etc..Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450 kg/m 3 following.Three is to lower water ash ratio, water ash of the general concrete ratio control below 0.6.Four is improvement the bone anticipate class to go together with, the Chan add powder ash from stove or efficiently reduce water etc. to come to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lower sprinkle of concrete to build temperature.Six is the in addition that the Chan add a have of fixed amount to reduce water and increase Su, slow Ning etc. function in the concrete, improvement the concrete mix to match a thing of mobility, protect water, lower water to turn hot, postpone hot Feng of emergence time.Seven is the heat season sprinkle to build can the adoption take to establish to hide sun plank etc. assistance measure control concrete of Wen Sheng, lower to sprinkle temperature of build the concrete.Eight is the temperature of big physical volume concrete should the dint relate to structure size, concrete structure size more big, temperature should dint more big, so want reasonable arrangement construction work preface,layering, cent the piece sprinkle to build, for the convenience of in spread hot, let up control.Nine is at great inner part constitution of the physical volume concrete cool off piping, cold water perhaps cold air cool off, let up concrete of inside outside difference in temperature.Ten is the supervision which strengthen concrete temperature, adopt to cool off in time, protection measure.11 is to reserve temperature constringency to sew.12 is to let up to control, sprinkle proper before building concrete in the Ji rock and old concrete top build a 5 mm or so sand mat a layer or usage asphalt etc. material Tu2 Shua.13 is to strengthen concrete to protect, the concrete after sprinkle build use moist grass Lian in time, hemp slice's etc. overlay, and attention sprinkle water to protect, appropriate extension protect time, assurance the concrete surface be slow-moving cool off.At the cold season, concrete surface should constitution heat preservation measure, in order to prevent cold wave assault.14 is the allocation be a little amount in the concrete of reinforcing bar perhaps add fiber material concrete of temperature crack control at certain of scope inside.5.Crack and prevention that the chemical reaction causeAlkali bone's anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the reinforced concrete structure of because of chemical reaction but cause of crack.The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open crack.In this kind of crack general emergence concrete structure usage period, once appear very difficult remediable, so should at under construction adopt valid the measure carry on prevention.Main of prevention measure:While being to choose to anticipate with the alkali activity small freestone bone.Two is the in addition which choose to use low lye mire with low alkali or have no alkali.Three is the Chan which choose to use accommodation with anticipate to repress an alkali bone to anticipate reaction.Because the concrete sprinkle to build, flap Dao bad perhaps is a reinforcingbar protection layer thinner, the harmful material get into concrete to make reinforcing bar creation rust eclipse, the reinforcing bar physical volume of the rust eclipse inflation, cause concrete bulge crack, the crack of this kind type much is a crack lengthways, follow the position of reinforcing bar ually of prevent measure from have:One is assurance reinforcing bar protection the thickness of the layer.Two is a concrete class to go together with to want good.Three is a concrete to sprinkle to note and flap Dao airtight solid.Four is a reinforcing bar surface layer Tu2 Shua antisepsis coating.Crack processingThe emergence of the crack not only would influence structure of whole with just degree, return will cause the rust eclipse of reinforcing bar, acceleration concrete of carbonization, lower durable and anti- of concrete tired, anti- Shen ability.Therefore according to the property of crack and concrete circumstance we want differentiation to treat, in time processing, with assurance building of safety usage.The repair measure of the concrete crack is main to have the following some method:Surface repair method, infuse syrup, the Qian sew method, the structure reinforce a method, concrete displacement method, electricity chemistry protection method and imitate to living from heal method.Surface repair the method be a kind of simple, familiar of repair method, it main be applicable to stability and to structure loading the ability don't have the surface crack of influence and deep enter crack of processing.The processing measure that is usually is a surface in crack daubery cement syrup, the wreath oxygen gum mire or at concrete surface Tu2 Shua paint, asphalt etc. antisepsis material, at protection of in the meantime for keeping concrete from continue under the influence of various function to open crack, usually can adoption the surface in crack glue to stick glass fiber cloth etc. measure.1, infuse syrup, the Qian sew methodInfuse a syrup method main the concrete crack been applicable to haveinfluence or have already defend Shen request to the structure whole of repair, it is make use of pressure equipments gum knot the material press into the crack of concrete, gum knot the material harden behind and concrete formation one be whole, thus reinforce of purpose.The in common use gum knot material has the cement the syrup, epoxy, A Ji C Xi sour ester and gather ammonia ester to equalize to learn material.The Qian sew a method is that the crack be a kind of most in common use method in, it usually is follow the crack dig slot, the Qian fill Su in the slot or rigid water material with attain closing crack of purpose.The in common use Su material has PVC gum mire, plastics ointment, the D Ji rubber etc.;In common use rigid water material is the polymer cement sand syrup.2, the structure reinforce a methodWhen the crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure.The structure reinforce medium in common use main have the following a few method:The piece of enlargement concrete structure in every aspect accumulate, outside the Cape department of the Gou piece pack type steel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete compensation reinforce.3, concrete displacement methodConcrete displacement method is processing severity damage concrete of a kind of valid method, this method be first will damage of the concrete pick and get rid of, then again displacement go into new of concrete or other material.The in common use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup.4, the electricity chemistry protection methodThe electricity chemistry antisepsis is to make use of infliction electric field in lie the quality of electricity chemical effect, change concrete or reinforced concrete the environment appearance of the place, the bluntness turn reinforcing bar to attainthe purpose of antisepsis.Cathode protection method, chlorine salt's withdrawing a method, alkalescence to recover a method is a chemistry protection method in three kinds of in common use but valid method.The advantage of this kind of method is a protection method under the influence of environment factor smaller, apply reinforcing bar, concrete of long-term antisepsis, since can used for crack structure already can also used for new set up structure.5, imitate to living from legal moreImitate to living from heal the method be a kind of new crack treatment, its mimicry living creature organization secrete a certain material towards suffering wound part auto, but make the wound part heal of function, join some and special composition(such as contain to glue knot of the liquid Xin fiber or capsule) in the concrete of the tradition the composition, at concrete inner part formation the intelligence type imitate to living from heal nerve network system, be the concrete appear crack secrete a parts of liquid Xin fiber can make the crack re- heal.ConclusionThe crack is widespread in the concrete structure existence of a kind of phenomenon, it of emergence not only will lower the anti- Shen of building ability, influence building of usage function, and will cause the rust eclipse of reinforcing bar, the carbonization of concrete, lower the durable of material, influence building of loading ability, so want to carry on to the concrete crack earnest research, differentiation treat, adoption reasonable of the method carry on processing, and at under construction adopt various valid of prevention measure to prevention crack of emergence and development, assurance building and Gou piece safety, stability work.From《CANADIAN JOURNAL OF CIVIL ENGINEERING》中文原文：建筑施工混凝土裂缝的预防与处理混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题，本文对混凝土工程中常见的一些裂缝问题进行了探讨分析，并针对具体情况提出了一些预防、处理措施。

基础及基础工程外文翻译河北建筑工程学院毕业设计（论文）外文资料翻译系别：土木工程专业：土木工程班级： ********* 姓名： ********** 学号： ************** 外文出处：GEOLOGLCAL AND GEOTECHNICAL ENGINEERING附件：1、外文原文；2、外文资料翻译译文。

指导教师评语：签字：年月日1、外文原文（复印件）Foundation And Foundation EngineeringStrucures or other constructed works are supported on the earth by foundation. The word “foundation” may mean the earth itself, something placed in or on the earth to provide support, or a combinnation of the earth and the elements placed on it. The foundation for a multistory office building could be a combination for an earth-fill dam would be the natural soil or rock on which the dam is placed. Concrete footings or which or in which they are placed. The installed elements and the natural soil or rock of the earth form a foundation system; the soil and rock provide the ultimate support of the system. Foundation that are installed may be either soil-bearing or rock –bearing. The reactions of the soil or rock to the imposed loads generally determined how well the foundation system functions. In designing the installed portions, the designer must determine the safe pressue which can be used on the soil or rock and the amount of total settlement and differential settlement which the structure can withstand.The installed parts of the foundation system may be footings, mat foundations, slab foundations, and caissons or piles, all of which are used to transfer load from a supersteucture into the earth. These parts, which transmit load from the superstructure to the earth, are called the substructure.Footing Footing or spread foundations are used to spread the loads from columns or walls to the underlying soil or rock. Normally, footings are constructed of reinfored concrete. However, under some circumstances they may be constructed of plain concrete or masonary, when each footing supports only one column, it is square. Footings supporting two coumns are called combined footings and may be either rectangular or trapezoidal. Cantilever footings are used to building line or exterior wall. Footings supportsing walls are continuous footings.The sizes of footings are determined by dividing the loads to be imposed at the base of the footings by the allowable bearing pressure which can be imposed on the soil or rock of the earth. Most building codes and textbooks on foundations contain tables listing allowable bearing pressures for various types of soil and rock; however , these tables give only general classifications and descriptions of the soil or rock must be used with caution. More specific information about the soil or rock is normally obtained by drilling test borings, extracting soil or rock samples, performing laboratory tests on the samples, and making engineering must be given to the amount of settlement which may occur and the capability of the structure to withstand such settement. If settlement is problem it may be necessary to use an alternatefoundation type rather than footings or to enlarge the footings and decrease the bearing pressure.Grade beams may be used between exterior column footings to support walls, with the beams transferring the weight of the walls to the column footings. Beams are also used between interior column footings to act as braces or to support interior walls. Retaining walls are those walls subject to horizontal earth pressures due to the retention of earth behind them. The foundation for these will not slide when subjected to the horizontal earth pressure. In addition,retaining walls must be designed so they will not overturn. In frost-susceptible areas, footings must be placed below the frost line.Mat foundations Mat or raft foundations are large, thick, and usually heavily reinforced concrete mats which transfer loads from a number or colums and walls to the underlying soil or rock. Mats are also combined footings.,but are much larger than a footing uniform pressure to the underlying soil or rock. Mats are rigid and will act as a bridge over discontinuities in the soil or rock on which they are founded. Mats founded several meters below the ground surface, when combined with external walls, are termed floating foundations. The weight of the soil excavated from the ground surface to the bottom of the mat may be equal to approach the total weight of the structure. In this case, little or no new load is applied to the underlying supporting soil, and settlements of a structure may be minimal after construction.Slab foundations Slab foundations are used for light structures wherein the columns and walls are supportes directly on the floor slab. The floor slab is thickened and more heavily reinforced at the places where the column and wall loads are imposed.Special problems Groundwater is a major problem in connection with the design and installation of foundations where a substructure is to be placed below the groundwater level. Well points, pumping from deep wells, or pumping from sumps are methods used to dewater construction sites during foundation installation. Other methods which are less often used are freezing of the water in the soul, removal of water by electroosmosis, and the installation of cutoff walls made of pilling or grout around the periphery from within the excavation. If dewatering operations are perfromed in an area surrounded by existing structures, precautions must be taken to project them, as the lowering of the geoundwater may cause the soil on which they are supported to subside.If a basement is partially or totally below the groundwater level, its walls must be designed to withstand the hydrostatic pressure of the water on the outside in addition to the pressure from the soil backfill. An alternate procedure is to install a permanent system to remove watet outside the walls. Some substructure below groundwater level may at times besubjected to hydrostaic uplift forces which are greater than the downward forces imposed by the structures. In these cases, provisions must be to anchor the structures to prevent them from floating upward.Groundwater also causes problems by infiltrating though basement walls., slabs, and joints into the basement itself. This can be prevented or reduced by providing an external permanent drainage system that carries water away from the basenment, by encasing the walls and slabs in an permeability. Combinations of the foregoing are also used. Retaining walls and abutments ofen abutments can escape. The water pressure behind the walls is relieved as the water flows though the walls into an open external drainage system.Foundations placed on expansive soil are often subjected to distressing movement unless special precautions are taken. Expansive soil are those which swell and contract excessively with varying amounts of moissture. Problems can be overcome by installing foundations below the zone of significant change in moisture content and backfilling with nonexpansive materials, by altering the soil with an admixture such as lime or cement so that volumn changes do not occur, or by providing flexibility in the structure to accommodate movements.Underpinning of foundation is often necessary, and it may be either remedial or precautionary. Remedial underpinning is used to correct defects in existing froundations which may have settled excessively. If the structure is to be saved or returned to its original state, additional foundation support must be provided. Precautionary underpinning is used when new structure are to be installed adjacent to or beneath existing structures, as in the construction of city subways. Underpinning of foundation is a specialized construction technique. The work is generally performed in a confined space, such as the basement of a building, or in small pits excavated outside a building area. It is necessary to provide support for the loads of the existing structure while new foundations are installed. The new foundations may be footings which are placed deeper in the ground than the original foundations, or they may be piles or caissons.Underpinning of a wall footing may be performed by excavating pits adjacent to and beneath existing foundations. The pits are small, some 0.9m wide by 1.2m long. Horizontal sheeting is placed in the pits as excavation proceeds to prevent caving of the walls and undermining of the structure being underpinned. When the new bearing stratum is reached, forms are placed in the pit, and concrete is poured from the new bearing stratum up to within 76mm of the bottom of the old footing. After the new concrete has hardened, the 76mm space is packed by hand with a mixture of sand, cement, and a small amount of water. Called grout, themixture is packed very tightly into the space between the top of the new footing and the underside of the old footing. The pit underpinning process is repeated throughout the entirelength of the wall footing. The resulting new foundation may be a continuous wall or intermittent piers.One indisputable face is this: whatever the shape of a building or structure and whatever the nature and number of its supports, the whole weight of the building must come down to, and be supported by the ground. It is therefore essential that, for any propose structure, sufficient knowledge be obtained of the nature of the supporting soil and its load-bearing capacity.The purpose of a foundation is to convey the weight of a building to the soil in such a manner:(1)That excessive settlement will not occur;(2)That differential settlement of various sections of the building, which causescracks in the structure, will not occur;(3)That the soil will not fail under its load, thus causing no collapse of thebuilding.Compared with structural materials, such as steel and timber, soil is difficult to investigate scientifically. It can vary considerably in its properties on one building site both in horizontal and vertical directions.Until the 20th century, foundations were constucted mainly on the basis of experience. For important structures, deep trial pits were dug so that the soil could be examined for some distance below the surface, and sometimes loading tests on small area at the botton of the pits, were made to estimate the safe-bearing capacity of the soil.Some time about 1920 there began a more scientific approach to the behavior of soil. One of the earliest names, and a most important one, connected with this new science, is Dr. Karl Terzaghi, who made an extensive study of the properties of soils. Since 1920 much research has been carried out in many countries; many tests (site and laboratory) have been devised, and there is now a considerable literature on the subject of soil mechanics. Modern site investigations for important structures are carried out by specialist firms who have trained persomnel, equipment for drilling and boring and for extracting samples of soil, and facilities for making site and laboratory tests.All the material foeming the crust of the earth likely to be affected by the pressure of strutures is dicided by engineers into two major geoups: rocks and soils. The term “rock” is reserved for hard , rigid, and strongly cemented material, while “soil” is applied to the comparatively soft and loose materials.Soils without of organic deposits such as peat are broadly divided into two groups: cohesive and non-cohesive. Silts and clays are cohesive, while granular materials such assands and gravels are non-cohesive.Owing to the weight of a building or other structure, there is bound to be a certain amount of settlement. It was stated previously that force cannot be applied to any material without causing deformation. The total settlement of a building takes place in two stages:(1)Immediate settlement, as the building is being erected, due to elastic and plasticdeformation of the soil.(2)Consolidation settlement caused by the sequeezing-out of water contained in thepores of the soil and thus compressing the soil to a smaller volume.From the settlement point of view, non-cohesive soils such as sands and geavels are not very troublesome since they are only moderately compressible and are evey permeable (a permeable material is one which allows water through it easily). Consolidation settlement due to sequeezing-out of pore water therefore occurs very quickly during and soon after the erection of the strycture, and is comparatively small. Special attention, however, must be given to loose sands, which can show appreciable settlement if subjected to vibration.Cohesive soils such as clay have very low permeability, which means that squeezing of water from the pores due to consoildation settlement of the building is a slow process. Furthermore, the compressibility of most calys and silts is appreciable and there is a compressibility volume reduction under pressure. The final settlement of a structure founded on clay may therefore not occur until some years after erection and must be allowed for in design calculations.Clay is aslo a troublesome material when encounterd in shallow foundations (for houses and other small buildings). Cohesive soils dry out in the summer and spring; surface cracks can occur which may extend to about 0.3m in britain.Precast Piles Precast piles, which are usually square or octagonal in cross-section, are driven into the soil by repeated blows from a falling weighted or from a steam hammer. The piles are driven in until a certain number of blows produce only a small further penetration which has been predetermined by zalculations in accordance with the loads , and the piles will be called upon to supports .A simple illustation is that of knocking a timber stake into soil. The deeper the stake is driven into the geound, the greater is the frictional resistance and the harder it is to drive the stake downwards. When a pile is driven a sufficient distance, the resultant load it has to carry is usually supported partly by frictional force on the sides of the pile and partly by the bearing resistance of the soil under the foot of the pile.If the strata are of such a nature that the soil can offer negligible frictional resistance, the pile must be drien until it meets a hard strtum such as rock capable of supporting the full load.Alternatively the soil may be of such a nature that most of the trsistance to the downward artion of the weight of the building is provided by frictional resistance.Inspporting their loads, piles act as columns, except that the soil provides lateral restraint.Another method, as used by the Franki Compressed Pile Co, consists in driving a steel tube to the required depth and filling it with in-situ concrete. First, the bottom of the tube is sealed by a temporary gravel plug. The tube is then driven to the required depth by blows on this plug from a long heavy cylindrical hammer. Concrete is then placed in the tube and rammed so that a bulbous foot is produced (thus increasing bearing resistance). As the rammed concrete approaches the ground surface, the tube is geadually withdrawn.Bored Piles Driven piles displace and compress the soil. Then piles are bored in situ, the soil is removed by special boring tools to form cylindrial holes equal to the depths of the prepared piles. Steel reinforcenment is then inserted and concreted rammed in to form the pile, which frequently has a bulbous base due to heary ramming of the frist batch of concrete. In addition, bored piles are useful where headroom is restricted so that it is impossible to have long lengths of precast piles projecting above ground level.Cylinder Piles Cylinder foundations, 2m or more in diameter, have been employed for many years, the holes being made by excavating soil with hand or mechanically operated geabs. During the last few years new methods have developed for forming these large diameter holes. In one system, first used in the United States, angles(drills), varying from 1m to 2.3m in diameter, are used for boring holes which may be as much as 25m deep or more. The bottoms of the 2.3m diameter cylinders, and 2.3m for the 1m diameter cylinders. Large bearing areas are thus obtained; one of these piles in the London clay was designed to supporting a load of 2000 tones. One advantage of a large-diameter cylinder pile is that cap, which is required when the column has to be supported by a number of small-diameter piles.Piles Caps When small-diameter driven or bored piles are used, the number of piles required to suppore one column must be transferred to the piles by means of a foundation called a pile cap. Reinforcement is required in the cap to resist bending stresses, etc.2、外文资料翻译译文基础及基础工程建筑物或是已建成的工程是由基础下的地基土支撑着的。

Building construction concrete crack ofprevention and processingDimosi M《CANADIAN JOURNAL OF CIVILENGINEERING》Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure.Keyword: Concrete crack prevention processingForewordConcrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use functionnot a creation to after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering.Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and anti- Shen ability, influence building of external appearance, service life, severity will threat arrive people's life and property lot of all of crash of engineerings is because of the unsteady development of the crack with the result age science research with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of at under construction should as far as possible adopt a valid measure control crack creation, make the structure don't appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus.Concrete crack creation of the reason be a lot of and have alreadytransformed to cause of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reason cause of crack;Have outside carry the crack that the function cause;Protected environment not appropriate the crack etc. caused with chemical differentiation to treat in the actual engineering, work°out a problem according to the actual circumstance.In the concrete engineering the familiar crack and the prevention.1.Stem Suo crack and preventionStem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result:The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pull should dint but creation relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between mm, the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short to Suo crack usually the anti- Shen of influence concrete,cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc..Concrete stem the Suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant.Main prevention measure:While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can't big in match ratio design give settle of use water is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete construction want tobeappropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to is a constitution the accommodation is in the concrete structure of the constringency sew.Su constringency crack and preventionSu constringency is the concrete is before condense, surface because of lose water quicker but creation of Su constringency crack isgeneral at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning very small, perhaps concrete just eventuallyNing but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again can't resist its constringency, therefore creation influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature,wind velocity, relative humidity...etc.. Main prevention measure:One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of is to sprinkle before building concrete, water basic level and template even to soak is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities,protect in time. to sink crack and preventionThe creation which sink to sink crack is because of the structure foundation soil quality not and evenly, loose soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to decline with the result that;Perhaps because of template just degree shortage, the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the templateprop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation kind crack many is deep enter or pierce through sex crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or present 30 °s-45 ° Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion width under the influence of temperature variety foundation after transform stability sink to sink crack also basic tend in stability.Main prevention measure:One is rightness loose soft soil, return to fill soil foundation a construction at the upper part structure front should carry on necessity of Hang solid with is the strength that assurance template is enough and just degree, and prop up firm, and make the foundation be subjected to dintis keep concrete from sprinkle infusing the foundation in the process is soak by is time that template tore down to can't be too early, and want tonotice to dismantle a mold order of is at jelly soil top take to establish template to notice to adopt certain of prevention measure.crack and preventionTemperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete compare the earth area of the concrete after sprinkling to build, in the hardening the process, cement water turn a creation a great deal of of water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, each sign square the rice concrete will release a calories of kJ and make concrete internal thus the temperature rise to reach to 70 ℃or so even higher)Because the physical volume of concrete be more big, a great deal of water turn hot accumulate at the concrete inner part but not easy send forth, cause inner part the temperature hoick, but the concrete surface spread hot more quick, so formation inside outside of bigger difference in temperature, the bigger difference in temperature result in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull should pull should dint exceed the anti- of concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc., will cause concrete surface the temperature sharply descend, but creation constringency, surface constringency of the concrete be subjected to inner part concrete of control,creation very big of pull should dint but creation crack, this kind of crack usually just in more shallow scope of the concrete surface creation.The alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;The size bigger structure of the beam plank length, the crack run parallel with short side more;Thorough with pierce through sex of temperature crack general and short side direction parallelism or close parallelism, crack along long side cent the segment appear, in the center more width the size be different, be subjected to temperature variety influence more obvious, winter compare breadth, summer more concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin, but cold Suo crack of thick thin variety not too emergence of the this kind crack will cause the rust eclipse of reinforcing bar, the carbonization of concrete, the anti- jelly which lower concrete melt, anti- tired and anti- Shen ability etc..Main prevention measure:One is as far as possible choose to use low hot or medium hot water mire, like mineral residue cement, powder ash from stove cement...etc..Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450kg/m 3 is to lower water ash ratio, water ash of the general concrete ratio control below is improvement the bone anticipate class to go together with, the Chan add powder ash from stove or efficiently reduce water etc. to come to reduce cement dosage and lower water to turn is animprovement concrete of mix blend to process a craft, lower sprinkle of concrete to build is the in addition that the Chan add a have of fixed amount to reduce water and increase Su, slow Ning etc. function in the concrete, improvement the concrete mix to match a thing of mobility, protect water, lower water to turn hot, postpone hot Feng of emergence is the heat season sprinkle to build can the adoption take to establish to hide sun plank etc. assistance measure control concrete of Wen Sheng, lower to sprinkle temperature of build the is the temperature of big physical volume concrete should the dint relate to structure size, concrete structure size more big, temperature should dint more big, so want reasonable arrangement construction work preface, layering, cent the piece sprinkle to build, for the convenience of in spread hot, let up is at great inner part constitution of the physical volume concrete cool off piping, cold water perhaps cold air cool off, let up concrete of inside outside difference in is the supervision which strengthen concrete temperature, adopt to cool off in time, protection istoreserve temperature constringency to is to let up to control, sprinkle proper before building concrete in the Ji rock and old concrete top build a 5 mm or so sand mat a layer or usage asphalt etc. material Tu2 is to strengthen concrete to protect, the concrete after sprinkle build usemoist grass Lian in time, hemp slice's etc. overlay, and attention sprinkle water to protect, appropriate extension protect time, assurance the concrete surface be slow-moving cool the cold season, concrete surfaceshould constitution heat preservation measure, in order to prevent cold wave is the allocation be a little amount in the concrete of reinforcing bar perhaps add fiber material concrete of temperature crack control at certain of scope inside.and prevention that the chemical reaction causeAlkali bone's anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the reinforced concrete structure of because of chemical reaction but cause of crack. The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open this kind of crack general emergence concrete structure usage period, once appear very difficult remediable, so should at under construction adopt valid the measure carry on of prevention measure:While being to choose to anticipate with the alkali activity small freestone is the in addition which choose to use low lye mire with low alkali or have no is the Chan which choose to use accommodation with anticipate to repress an alkali bone to anticipate reaction.Because the concrete sprinkle to build, flap Dao bad perhaps is a reinforcing bar protection layer thinner, the harmful material get into concrete to make reinforcing bar creation rust eclipse, the reinforcing bar physical volume of the rust eclipse inflation,cause concrete bulge crack, the crack of this kind type much is a crack lengthways, follow the position of reinforcing bar of prevent measure from have:One is assurance reinforcing bar protection the thickness of the is a concrete class to go together with to want is a concrete to sprinkle to note and flap Dao airtight is a reinforcing bar surface layer Tu2 Shua antisepsis coating.Crack processingThe emergence of the crack not only would influence structure of whole with just degree, return will cause the rust eclipse of reinforcing bar, acceleration concrete of carbonization, lower durable and anti- of concrete tired, anti- Shenaccording to the property of crack and concrete circumstance we want differentiation to treat, in time processing, with assurance building of safety usage.The repair measure of the concrete crack is main to have the following some method:Surface repair method, infuse syrup, the Qian sew method, the structure reinforce a method, concrete displacement method, electricity chemistry protection method and imitate to living from heal method. Surface repair the method be a kind of simple, familiar of repair method, it main be applicable to stability and to structure loading the ability don't have the surface crack of influence and deep enter crack of processing measure that is usually is a surface in crack daubery cement syrup, the wreath oxygen gum mire or at concrete surface Tu2 Shua paint, asphaltetc. antisepsis material, at protection of in the meantime for keeping concrete from continue under the influence of various function to open crack, usually can adoption the surface in crack glue to stick glass fiber cloth etc. measure.1, infuse syrup, the Qian sew methodInfuse a syrup method main the concrete crack been applicable to have influence or have already defend Shen request to the structure whole of repair, it is make use of pressure equipments gum knot the material press into the crack of concrete, gum knotthe material harden behind and concrete formation one be whole, thus reinforce of in common use gum knot material has the cement the syrup, epoxy, A Ji CXi sour ester and gather ammonia ester to equalize to learn material.The Qian sew a method is that the crack be a kind of most in common use method in, it usually is follow the crack dig slot, the Qian fill Su in the slot or rigid water material with attain closing crack of in common use Su material has PVC gum mire, plastics ointment, the D Ji rubber etc.;In common use rigid water material is the polymer cement sand syrup.2, the structure reinforce a methodWhen the crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure reinforce medium in common use main have thefollowing a few methodThe piece of enlargement concrete structure in every aspect accumulate, outside the Cape department of the Gou piece pack type steel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete compensation reinforce.3, concrete displacement methodConcrete displacement method is processing severity damage concrete of a kind of valid method, this method be first will damage of the concrete pick and get rid of, then again displacement go into new of concrete or other in common use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup.4, the electricity chemistry protection methodThe electricity chemistry antisepsis is to make use of infliction electric field in lie the quality of electricity chemical effect, change concrete or reinforced concrete the environment appearance of the place, the bluntness turn reinforcing bar to attain the purpose of protection method, chlorine salt's withdrawing a method, alkalescence to recover a method is a chemistry protection method in three kinds of in common use but valid advantage of this kind of method is a protection method under the influence of environment factor smaller, apply reinforcing bar, concrete of long-term antisepsis, since can used for crack structure already can also used for new set up structure.5, imitate to living from legal moreImitate to living from heal the method be a kind of new crack treatment, its mimicry living creature organization secrete a certain material towards suffering wound part auto, but make the wound part heal of function, join some and special composition(suchas contain to glue knot of the liquid Xin fiber or capsule) in the concrete of the tradition the composition, at concrete inner part formation the intelligence type imitate to living from heal nerve network system, be the concrete appear crack secrete a parts of liquid Xin fiber can make the crack re- heal.ConclusionThe crack is widespread in the concrete structure existence of a kind of phenomenon, it of emergence not only will lower the anti- Shen of building ability, influence buildingof usage function, and will cause the rust eclipse of reinforcing bar, the carbonization of concrete, lower the durable of material, influence building of loading ability, so want to carry on to the concrete crack earnest research, differentiation treat, adoption reasonable of the method carry on processing, and at under construction adopt various valid of prevention measure to prevention crack of emergence and development, assurance building and Gou piece safety, stability work.译文：建筑施工混凝土裂痕的预防与处置迪默斯M《加拿大土木工程学报》摘要混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题本文对混凝土工程中常见的一些裂痕问题进行了探讨分析并针对具体情况提出了一些预防、处置办法。

地下室设计深基坑中英文对照外文翻译文献中英文对照外文翻译(文档含英文原文和中文翻译) Deep E x ca v a t ion s ABSTR ACT ：All major topics in the design of in-situ retaining systems for deep excavations in urban areas are outlined. Type of wall, water related problems and water pressures, lateral earth pressures, type of support, solution to earth retaining walls, types of failure, internal and external stability problems. KEYW OR DS: deep excavation; retaining wall; earth pressure; INTR ODUCTION Numbers of deep excavation pits in city centers are increasing every year. Buildings, streets surrounding excavation locations and design of very deepbasements make excavations formidable projects. This chapter has been organized in such a way that subjects related to deep excavation projects are summarized in several sections in the order of design routine. These are types of in-situ walls, water pressures and water related problems. Earth pressures in cohesionless and cohesive soils are presented in two different categories. Ground anchors, struts and nails as supporting elements are explained. Anchors are given more emphasis compared to others due to widespread use observed in the recent years. Stability of retaining systems are discussed as internal and external stability. Solution of walls for shears, moments, displacements and support reactions under earth and water pressures are obtained making use of different methods of analysis. A pile wall supported by anchors is solved by threemethods and the results are compared. Type of wall failures, observed wall movements and instrumentation of deep excavation projects are summarized.1. TYPES OF EARTH R ETAINING WAL L S Introduction More than several types of in-situ walls are used to support excavations. The criteria for the selection of type of wall are size of excavation, ground conditions, groundwater level, vertical and horizontal displacements of adjacent ground and limitations of various structures, availability of construction, cost, speed of work and others. One of the main decisions is the water-tightness of wall. The following types of in-situ walls will be summarized below; 1. Braced walls, soldier pile and lagging walls2. Sheet-piling or sheet pile walls3. Pile walls (contiguous, secant)4. Diaphragm walls or slurry trench walls5. Reinforced concrete (cast-in-situ or prefabricated) retaining walls6. Soil nail walls7. Cofferdams8. Jet-grout and deep mixed walls9. Top-down construction 10. Partial excavation or island method Br aced Walls Excavation proceeds step by step after placement of soldier piles or so called king posts around the excavation at about 2 to 3 m intervals. These may be steel H, I or WF sections. Rail sections and timber are also used. At each level horizontal waling beams and supporting elements (struts, anchors, nails) are constructed. Soldier piles are driven or commonly placed in bored holes in urban areas, and timber lagging is placed between soldier piles during the excavation. Various details of placement of lagging are available, however, precast units, in-situ concrete or shotcrete may also be used as alternative to timber.Depending on ground conditions no lagging may be provided in relatively shallow pits. Historically braced walls are strut supported. They had been used extensively before the ground anchor technology was developed in 1970 s. Soils with some cohesion and without water table are usually suitable for this type of construction or dewatering is accompanied if required and allowed. Strut support is commonly preferred in narrow excavations for pipe laying or similar works but also used in deep and large excavations (See Fig ). Ground anchor support is increasingly used and preferred due to access for construction works and machinery. Waling beams may be used or anchors may be placed directly on soldier piles without any beams. Sheet-piling or Sheet Pile Walls Sheet pile is a thin steel section (7-30 mm thick) 400-500 mm wide. It ismanufactured in different lengths and shapes like U, Z and straight line sections (Fig. ). There are interlocking watertight grooves at the sides, and they are driven into soil by hammering or vibrating. Their use is often restricted in urbanized areas due to environmental problems like noise and vibrations. New generation hammers generate minimum vibration and disturbance, and static pushing of sections have been recently possible. In soft ground several sections may be driven using a template. The end product is a watertight steel wall in soil. One side (inner) of wall is excavated step by step and support is given by struts or anchor. Waling beams (walers) are frequently used. They are usually constructed in water bearing soils. Steel sheet piles are the most common but sometimes reinforced concrete precast sheet pile sections are preferred in softsoils if driving difficulties are not expected. Steel piles may also encounter driving difficulties in very dense, stiff soils or in soils with boulders. Jetting may be accompanied during the process to ease penetration. Steel sheet pile sections used in such difficult driving conditions are selected according to the driving resistance rather than the design moments in the project. Another frequently faced problem is the flaws in interlocking during driving which result in leakages under water table. Sheet pile walls are commonly used for temporary purposes but permanent cases are also abundant. In temporary works sections are extracted after their service is over, and they are reused after maintenance. This process may not be suitable in dense urban environment. Pile Walls In-situ pile retaining walls are very popular due to their availabilityand practicability. There are different types of pile walls (Fig. ). In contiguous (intermittent) bored pile construction, spacing between the piles is greaterthan the diameter of piles. Spacing is decided based on type of soil and level of design moments but it should not be too large, otherwise pieces of lumps etc. drop and extra precautions are needed. Cohesive soils or soils having some cohesion are suitable. No water table should be present. Acceptable amount of water is collected at the base and pumped out. Common diameters are , , m. Waling beams (usually called ?breasting beams ) are Tangent piles with grouting in between are used when secant piling or diaphragm walling equipment is not available ( in cases where ground water exists). Poor workmanship creates significant problems. Secant bored pile walls are formed bykeeping spacing of piles less than diameter (S There is also need for place for the plant. It may be constructed “hard-hard”as well as “soft-hard”. “S oft”concrete pile contains low cement content and some bentonite. Primary unreinforced piles are constructed first and then reinforced secondary piles are formed by cutting the primary piles. Pile construction methods may vary in different countries for all type of pile walls like full casing support, bentonite support, continuous flight auger (CFA) etc. mostly reinforced concrete but sheet pile sections or steel beams are also used. Diaphr agm Walls Diaphragm wall provides structural support and water tightness. It is a classical technique for many deep excavation projects, large civil engineering works, underground car parks, metro pits etc. especially under water table. Thesereinforced concrete diaphragm (continuous) walls are also called slurry trench walls due to the reference given to the construction technique where excavation of wall is made possible by filling and keeping the wall cavity full with bentonite-water mixture during excavation to prevent collapse of the excavated vertical surfaces. Wall thickness varies between m and m. The wall is constructed panel by panel in full lengths are 2 m to 10 m. Short lengths ( m) are selected in unstable soils or under very high surcharges. Nowadays depth of panels water stops exceeded 100 m, excavation depths exceeded 50 m. Different panel shapes other than the conventional straight section like T, L, H, Y, + are possible to form and used for special purposes. Panel excavation is made by cable or kelly supported buckets and by a recent designcalled ?cutter or ?hydrofraise which is a pair of hydraulically operated rotating disks provided with hard cutting tools. Excavation in rock is possible. Slurry wall technique is a specialized technique and apart from the bucket or the frame carrying the cutter equipment like crawler crane, pumps, tanks, desanding equipment, air lifts, screens, cyclones, silos, mixers, extractor are needed. Tremie concrete is placed in the slurry starting from the bottom after lowering reinforcement cages. Joint between the panels is a significant detail in water bearing soils and steel pipe, H-beam or water stops are used. R einforced C oncrete R eta ining Walls Excavation in Stages It is a common type of staged excavation wall usually supported by ground anchors. Soils with some cohesion are suitable because eachstage is first excavated before formwork and concrete placement. No water table or appreciable amount of water should be present. Sometimes micropile support is given if required due to expected cave-ins. Soil Nail Walls Similar to the method above excavation is made step by step ( to 2 m high). Shotcrete is common for facing and wiremesh is used. Soft facing is also possible making use of geotextiles. Hole is drilled, ordinary steel bars are lowered, and grout is placed without any pressure. Soil should be somewhat cohesive and no water table or significant water flow should be present. Coffer dams Cofferdam is a temporary earth retaining structure to be able to make excavation for construction activities. It is usually preferred in the coastal and sea environment like bridge piers and abutments in rivers, lakes etc., wharves, quay walls, docks, break waters andother structures for shore protection, large waterfront structures such as pump houses, subjected to heavy vertical and horizontal loads. Sheet piling is commonly used in various forms other than conventional walls like circular cellular bodies or double walls connected inside and filled with sand. Stability is maintained by sheeting driven deeper than base, sand body between sheeting and inside tie rods. Earth embankments and concrete bodies are also used. Contiguous, tangent, secant piles or diaphragm walls are constructed in circular shapes, and no internal bracing or anchoring is used to form a cofferdam. Reinforced concrete waling beams support by arching. Shafts are also made with this method. Large excavations or project details may require additional lateral support. J et Grout and Deep M ixed Walls Retainingwalls are made by single to triple row of jet grout columns or deep mixed columns. There is a soil mixed wall(SMW) technique specially developed for wall construction where H sections are used for reinforcement. Single reinforcing bar is placed in the central hole opened for jet grout columns. Anchors, nails or struts may be used for support. Top Down Constr uction Retaining structure (generally diaphragm wall) is designed and constructed as permanent load bearing walls of basement. Piles or barettes are similarly placed to complete the structural frame. Top slab is cast at the ground surface level, and excavation is made under the slab by smaller sized excavators and continued down forming basement slabs at each level. There are special connection details. Top down method is preferred in highly populated city centerswhere horizontal and vertical displacements are very critical, and anchors and struts are very difficult to use due to complex underground facilities and lifeline structures and site operations are difficult to perform. Pa r tia l Excavation or Island M ethod It is possible to give strut support to retaining walls at a later stage after constructing central sections of a building in large size excavations. Core of the structure is built at the central part making sloped excavations at peripheral areas and then the core frame is used to give support to walls (Figure ). It may be more practical and construction time may be less compared to conventional braced system. This method may not be suitable in soft and weak soils due to stability and deformation problems during sloped excavations. 2. EARTH PR ESSUR ES ON IN-SITU R ETAININGWAL L S Introduction Earth pressures on in-situ retaining walls are rather different than those on ordinary retaining walls due to the supporting elements. Free displacement of walls are not allowed. Type of support affects the distribution of earth pressure. Strut loads were measured in strutted excavations in many countries in the past, and recommendations were given. Ground anchor technology is relatively new, and data on instrumented anchored walls for total lateral。

土木工程建筑外文文献及翻译土木工程建筑外文文献及翻译Cyclic behavior of steel moment frame connections under varying axial load and lateral displacementsAbstractThis paper discusses the cyclic behavior of four steel moment connections tested under variable axial load and lateral displacements. The beam specim- ens consisted of a reducedbeam section, wing plates and longitudinal stiffeners. The test specimens were subjected to varying axial forces and lateral displace- ments to simulate the effects on beams in a Coupled-Girder Moment-Resisting Framing system under lateral loading. The test results showed that the specim- ens responded in a ductile manner since the plastic rotations exceeded 0.03 rad without significant drop in the lateral capacity. The presence of the longitudin- al stiffener assisted in transferring the axial forces and delayed the formation of web local buckling.1. IntroductionAimed at evaluating the structural performance of reduced-beam section(RBS) connections under alternated axial loading and lateral displacement, four full-scale specimens were tested. These tests were intended to assess the performance of the moment connection design for the Moscone Center Exp- ansion under the Design Basis Earthquake (DBE) and the Maximum Considered Earthquake (MCE). Previous research conducted on RBS moment connections [1,2] showed that connections with RBS profiles can achieve rotations in excess of 0.03 rad. However, doubts have been cast on the quality of the seismic performance of theseconnections under combined axial and lateral loading.The Moscone Center Expansion is a three-story, 71,814 m2 (773,000 ft2) structure with steel moment frames as its primary lateral force-resisting system. A three dimensional perspective illustration is shown in Fig. 1. The overall height of the building, at the highest point of the exhibition roof, is approxima- tely 35.36 m (116ft) above ground level. The ceiling height at the exhibition hall is 8.23 m (27 ft) , and the typical floor-to-floor height in the building is 11.43 m (37.5 ft). The building was designed as type I according to the requi- rements of the 1997 Uniform Building Code. The framing system consists of four moment frames in the East–West direct- ion, one on either side of the stair towers, and four frames in the North–South direction, one on either side of the stair and elevator cores in the east end and two at the west end of the structure [4]. Because of the story height, the con- cept of the Coupled-Girder Moment-Resisting Framing System (CGMRFS) was utilized.By coupling the girders, the lateral load-resisting behavior of the moment framing system changes to one where structural overturning moments are resisted partially by an axial compression–tension couple across the girder system, rather than only by the individual flexural action of the girders. As a result, a stiffer lateral load resisting system is achieved. The vertical element that connects the girders is referred to as a coupling link. Coupling links are analogous to and serve the same structural role as link beams in eccentrically braced frames. Coupling links are generally quite short, having a large shear- to-moment ratio.Under earthquake-type loading, the CGMRFS subjects its girders to wariab- ble axial forces in addition to their endmoments. The axial forces in theFig. 1. Moscone Center Expansion Project in San Francisco, CAgirders result from the accumulated shear in the link.2. Analytical model of CGMRFNonlinear static pushover analysis was conducted on a typical one-bay model of the CGMRF. Fig. 2 shows the dimensions and the various sections of the 10 in) and the ?254 mm (1 1/8 in ?model. The link flange plates were 28.5 mm 18 3/4 in). The SAP 2000 computer ?476 mm (3 /8 in ?web plate was 9.5 mm program was utilized in the pushover analysis [5]. The frame was characterized as fully restrained(FR). FR moment frames are those frames for 1170 which no more than 5% of the lateral deflections arise from connection deformation [6]. The 5% value refers only to deflection due to beam–column deformation and not to frame deflections that result from column panel zone deformation [6, 9].The analysis was performed using an expected value of the yield stress and ultimate strength. These values were equal to 372 MPa (54 ksi) and 518 MPa (75 ksi), respective ly. The plastic hinges’ load–deformation behavior was approximated by the generalized curve suggested by NEHRP Guidelines for the Seismic Rehab ilitation of Buildings [6] as shown in Fig. 3. △y was calcu- lated based on Eqs. (5.1) and (5.2) from [6], as follows: P–M hinge load–deformation model points C, D and E are based on Table 5.4 from [6] for△y was taken as 0.01 rad per Note 3 in [6], Table 5.8. Shear hinge load- load–deformation model points C, D and E are based on Table 5.8 [6], Link Beam, Item a. A strain hardening slope between points B and C of 3% of the elastic slope was assumedfor both models.The following relationship was used to account for moment–axial load interaction [6]:where MCE is the expected moment strength, ZRBS is the RBS plastic section modulus (in3), is the expected yield strength of the material (ksi), P is the axial force in the girder (kips) and is the expected axial yield force of the RBS, equal to (kips). The ultimate flexural capacities of the beam and the link of the model are shown in Table 1.Fig. 4 shows qualitatively the distribution of the bending moment, shear force, and axial force in the CGMRF under lateral load. The shear and axial force in the beams are less significant to the response of the beams as compared with the bending moment, although they must be considered in design. The qualita- tive distribution of internal forces illustrated in Fig. 5 is fundamentally the same for both elastic and inelastic ranges of behavior. The specific values of the internal forces will change as elements of the frame yield and internal for- ces are redistributed. The basic patterns illustrated in Fig. 5, however, remain the same.Inelastic static pushover analysis was carried out by applying monotonically increasing lateral displacements, at the top of both columns, as shown in Fig. 6. After the four RBS have yielded simultaneously, a uniform yielding in the web and at the ends of the flanges of the vertical link will form. This is the yield mechanism for the frame , with plastic hinges also forming at the base of the columns if they are fixed. The base shear versus drift angle of the model is shown in Fig. 7 . The sequence of inelastic activity in the frame is shown on the figure. An elastic component, a long transition (consequence of the beam plastic hinges being formed simultaneously) and a narrow yield plateaucharacterize the pushover curve.The plastic rotation capacity, qp, is defined as the total plastic rotation beyond which the connection strength starts to degrade below 80% [7]. This definition is different from that outlined in Section 9 (Appendix S) of the AISC Seismic Provisions [8, 10]. Using Eq. (2) derived by Uang and Fan [7], an estimate of the RBS plastic rotation capacity was found to be 0.037 rad:Fyf was substituted for Ry?Fy [8], where Ry is used to account for the differ- ence between the nominal and the expected yield strengths (Grade 50 steel, Fy=345 MPa and Ry =1.1 are used).3. Experimental programThe experimental set-up for studying the behavior of a connection was based on Fig. 6(a). Using the plastic displacement dp, plastic rotation gp, and plastic story drift angle qp shown in the figure, from geometry, it follows that:And:in which d and g include the elastic components. Approximations as above are used for large inelastic beam deformations. The diagram in Fig. 6(a) suggest that a sub assemblage with displacements controlled in the manner shown in Fig. 6(b) can represent the inelastic behavior of a typical beam in a CGMRF.The test set-up shown in Fig. 8 was constructed to develop the mechanism shown in Fig. 6(a) and (b). The axial actuators were attached to three 2438 mm × 1219 mm ×1219 mm (8 ft × 4 ft × 4 ft) RC blocks. These blocks were tensioned to the laboratory floor by means of twenty-four 32 mm diameter dywidag rods. This arrangement permitted replacement of the specimen after each test.Therefore, the force applied by the axial actuator, P, can beresolved into two or thogonal components, Paxial and Plateral. Since the inclination angle of the axial actuator does not exceed , therefore Paxial is approximately equal to P [4]. However, the lateral 3.0 component, Plateral, causes an additional moment at the beam-to column joint. If the axial actuators compress the specimen, then the lateral components will be adding to the lateral actuator forces, while if the axial actuators pull the specimen, the Plateral will be an opposing force to the lateral actuators. When the axial actuators undergoaxial actuators undergo a lateral displacement _, they cause an additional moment at the beam-to-column joint (P-△effect). Therefore, the moment at the beam-to column joint is equal to: where H is the lateral forces, L is the arm, P is the axial force and _ is the lateral displacement.Four full-scale experiments of beam column connections were conducted.The member sizes and the results of tensile coupon tests are listed in Table 2All of the columns and beams were of A572 Grade 50 steel (Fy 344.5 MPa). The actual measured beam flange yield stress value was equal to 372 MPa (54 ksi), while the ultimate strength ranged from 502 MPa (72.8 ksi) to 543 MPa (78.7 ksi).Table 3 shows the values of the plastic moment for each specimen (based on measured tensile coupon data) at the full cross-section and at the reduced section at mid-length of the RBS cutout.The specimens were designated as specimen 1 through specimen 4. Test specimens details are shown in Fig. 9 through Fig. 12. The following features were utilized in the design of the beam–column connection:The use of RBS in beam flanges. A circular cutout was provided, as illustr- ated in Figs. 11 and 12. For all specimens, 30% of the beam flange width was removed. The cuts were made carefully, and then ground smooth in a direct- tion parallel to the beam flange to minimize notches.Use of a fully welded web connection. The connection between the beam web and the column flange was made with a complete joint penetration groove weld (CJP). All CJP welds were performed according to AWS D1.1 Structural Welding Code Use of two side plates welded with CJP to exterior sides of top and bottom beam flan- ges, from the face of the column flange to the beginning of the RBS, as shown in Figs. 11 and 12. The end of the side plate was smoothed to meet the beginning of the RBS. The side plates were welded with CJP with the column flanges. The side plate was added to increase the flexural capacity at the joint location, while the smooth transition was to reduce the stress raisers, which may initiate fractureTwo longitudinal stiffeners, 95 mm × 35 mm (3 3/4 in × 1 3/8 in), were welded with 12.7 mm (1/2 in) fillet weld at the middle height of the web as shown in Figs. 9 and 10. The stiffeners were welded with CJP to column flanges.Removal of weld tabs at both the top and bottom beam flange groove welds. The weld tabs were removed to eliminate any potential notches introduced by the tabs or by weld discontinuities in the groove weld run out regionsUse of continuity plates with a thickness approximately equal to the beam flange thickness. One-inch thick continuity plates were used for all specimens.While the RBS is the most distinguishing feature of these test specimens, the longitudinal stiffener played an important role indelaying the formation of web local buckling and developing reliable connection4. Loading historySpecimens were tested by applying cycles of alternated load with tip displacement increments of _y as shown in Table 4. The tip displacement of the beam was imposed by servo-controlled actuators 3 and 4. When the axial force was to be applied, actuators 1 and 2 were activated such that its force simulates the shear force in the link to be transferred to the beam. 0.5_y. After The variable axial force was increased up to 2800 kN (630 kip) at that, this lo- ad was maintained constant through the maximum lateral displacement.maximum lateral displacement. As the specimen was pushed back the axialforce remained constant until 0.5 y and then started to decrease to zero as the specimen passed through the neutral position [4]. According to the upper bound for beam axial force as discussed in Section 2 of this paper, it was concluded that P =2800 kN (630 kip) is appropriate to investigate this case in RBS loading. The tests were continued until failure of the specimen, or until limitations of the test set-up were reached.5. Test resultsThe hysteretic response of each specimen is shown in Fig. 13 and Fig. 16. These plots show beam moment versus plastic rotation. The beam moment is measured at the middle of the RBS, and was computed by taking an equiva- lent beam-tip force multiplied by the distance between the centerline of the lateral actuator to the middle of the RBS (1792 mm for specimens 1 and 2, 3972 mm for specimens 3 and 4). The equivalent lateral force accounts for the additional moment due to P–△effect. Therotation angle was defined as the lateral displacement of the actuator divided by the length between the centerline of the lateral actuator to the mid length of the RBS. The plastic rotation was computed as follows [4]:where V is the shear force, Ke is the ratio of V/q in the elastic range. Measurements and observations made during the tests indicated that all of the plastic rotation in specimen 1 to specimen 4 was developed within the beam. The connection panel zone and the column remained elastic as intended by design.5.1. Specimens 1 and 2The responses of specimens 1 and 2 are shown in Fig. 13. Initial yielding occurred during cycles 7 and 8 at 1_y with yielding observed in the bottom flange. For all test specimens, initial yielding was observed at this location and attributed to the moment at the base of the specimen [4]. Progressing through the loading history, yielding started to propagate along the RBS bottom flange. During cycle 3.5_y initiation of web buckling was noted adjacent to the yielded bottom flange. Yielding started to propagate along the top flange of the RBS and some minor yielding along the middle stiffener. During the cycle of 5_y with the increased axial compression load to 3115 KN (700 kips) a severe web buckle developed along with flange local buckling. The flange and the web local buckling became more pronounced with each successive loading cycle. It should be noted here that the bottom flange and web local buckling was not accompanied by a significant deterioration in the hysteresis loops.A crack developed in specimen 1 bottom flange at the end of the RBS where it meets the side plate during the cycle 5.75_y. Upon progressing through the loading history, 7_y, the crackspread rapidly across the entire width of the bottom flange. Once the bottom flange was completely fractured, the web began to fracture. This fracture appeared to initiate at the end of the RBS，then propagated through the web net section of the shear tab, through the middle stiffener and the through the web net section on the other side of the stiffener. The maximum bending moment achieved on specimen 1 during theDuring the cycle 6.5 y, specimen 2 also showed a crack in the bottom flange at the end of the RBS where it meets the wing plate. Upon progressing thou- gh the loading history, 15 y, the crack spread slowly across the bottom flan- ge. Specimen 2 test was stopped at this point because the limitation of the test set-up was reached.The maximum force applied to specimens 1 and 2 was 890 kN (200 kip). The kink that is seen in the positive quadrant is due to the application of the varying axial tension force. The load-carrying capacity in this zone did not deteriorate as evidenced with the positive slope of the force–displacement curve. However, the load-carrying capacity deteriorated slightly in the neg- ative zone due to the web and the flange local buckling.Photographs of specimen 1 during the test are shown in Figs.14 and 15. Severe local buckling occurred in the bottom flange and portion of the web next to the bottom flange as shown in Fig. 14. The length of this buckle extended over the entire length of the RBS. Plastic hinges developed in the RBS with extensive yielding occurring in the beam flanges as well as the web. Fig. 15 shows the crack that initiated along the transition of the RBS to the side wing plate. Ultimate fracture of specimen 1 was caused by a fracture in the bottom flange. This fracture resulted in almost total loss of the beam- carrying capacity. Specimen 1 developed0.05 rad of plastic rotation and showed no sign of distress at the face of the column as shown in Fig. 15.5.2. Specimens 3 and 4The response of specimens 3 and 4 is shown in Fig. 16. Initial yielding occured during cycles 7 and 8 at 1_y with significant yielding observed in the bottom flange. Progressing through the loading history, yielding started to propagate along the bottom flange on the RBS. During cycle 1.5_y initiation of web buckling was noted adjacent to the yielded bottom flange. Yielding started to propagate along the top flange of the RBS and some minor yielding along the middle stiffener. During the cycle of 3.5_y a severe web buckle developed along with flange local buckling. The flange and the web local buckling bec- ame more pronounced with each successive loading cycle.During the cycle 4.5 y, the axial load was increased to 3115 KN (700 kips) causing yielding to propagate to middle transverse stiffener. Progressing through the loading history, the flange and the web local buckling became more severe. For both specimens, testing was stopped at this point due to limitations in the test set-up. No failures occurred in specimens 3 and 4. However, upon removing specimen 3 to outside the laboratory a hairline crack was observed at the CJP weld of the bottom flange to the column.The maximum forces applied to specimens 3 and 4 were 890 kN (200 kip) and 912 kN (205 kip). The load-carrying capacity deteriorated by 20% at the end of the tests for negative cycles due to the web and the flange local buckling. This gradual reduction started after about 0.015 to 0.02 rad of plastic rotation. The load-carrying capacity during positive cycles (axial tension applied in the girder) did not deteriorate as evidenced with the slope of the force–displacement envelope for specimen 3 shownin Fig. 17.A photograph of specimen 3 before testing is shown in Fig.18. Fig. 19 is aFig. 16. Hysteretic behavior of specimens 3 and 4 in terms of moment at middle RBS versus beam plastic rotation.photograph of specimen 4 taken after the application of 0.014 rad displacem- ent cycles, showing yielding and local buckling at the hinge region. The beam web yielded over its full depth. The most intense yielding was observed in the web bottom portion, between the bottom flange and the middle stiffener. The web top portion also showed yielding, although less severe than within the bottom portion. Yielding was observed in the longitudinal stiffener. No yiel- ding was observed in the web of the column in the joint panel zone. The un- reduced portion of the beam flanges near the face of the column did not show yielding either. The maximum displacement applied was 174 mm, and the maximum moment at the middle of the RBS was 1.51 times the plastic mom ent capacity of the beam. The plastic hinge rotation reached was about 0.032 rad (the hinge is located at a distance 0.54d from the column surface,where d is the depth of the beam).5.2.1. Strain distribution around connectionThe strain distribution across the flanges–outer surface of specimen 3 is shown in Figs. 20 and 21. The readings and the distributions of the strains in specimens 1, 2 and 4 (not presented) showed a similar trend. Also the seque- nce of yielding in these specimens is similar to specimen 3.The strain at 51 mm from the column in the top flange–outer surface remained below 0.2% during negative cycles. The top flange, at the same location, yielded in compression only Thelongitudinal strains along the centerline of the bottom–flange outer face are shown in Figs. 22 and 23 for positive and negative cycles, respectively. From Fig.23, it is found that the strain on the RBS becomes several times larg- er than that near the column after cycles at –1.5_y; this is responsible for theflange local buckling. Bottom flange local buckling occurred when the average strain in the plate reached the strain-hardening value (esh _ 0.018) and the reduced-beam portion of the plate was fully yielded under longitudinal stresses and permitted the development of a full buckled wave.5.2.2. Cumulative energy dissipatedThe cumulative energy dissipated by the specimens is shown in Fig. 24. The cumulative energy dissipated was calculated as the sum of the areas enclosed the lateral load–lateral displacement hysteresis loops. Energy dissipation sta- rted to increase after cycle 12 at 2.5 y (Fig. 19). At large drift levels, energy dissipation augments significantly with small changes in drift. Specimen 2 dissipated more energy than specimen 1, which fractured at RBS transition. However, for both specimens the trend is similar up to cycles at q =0.04 radIn general, the dissipated energy during negative cycles was1.55 times bigger than that for positive cycles in specimens 1 and2. For specimens 3 and 4 the dissipated energy during negative cycles was 120%, on the average, that of the positive cycles. The combined phenomena of yielding, strain hardening, in-plane and out- of-plane deformations, and local distortion all occurred soon after the bottom flange RBS yielded.6. ConclusionsBased on the observations made during the tests, and on the analysis of the instrumentation, the following conclusions weredeveloped:1. The plastic rotation exceeded the 3% radians in all test specimens.2. Plastification of RBS developed in a stable manner.3. The overstrength ratios for the flexural strength of the test specimens were equal to 1.56 for specimen 1 and 1.51 for specimen4. The flexural strength capacity was based on the nominal yield strength and on the FEMA-273 beam–column equation.4. The plastic local buckling of the bottom flange and the web was not accompanied by a significant deterioration in the load-carrying capacity.5. Although flange local buckling did not cause an immediate degradation of strength, it did induce web local buckling.6. The longitudinal stiffener added in the middle of the beam web assisted in transferring the axial forces and in delaying the formation of web local buckling. How ever, this has caused a much higher overstrength ratio, which had a significant impact on the capacity design of the welded joints, panel zone and the column.7. A gradual strength reduction occurred after 0.015 to 0.02 rad of plastic rotation during negative cycles. No strength degradation was observed during positive cycles.8. Compression axial load under 0.0325Py does not affect substantially the connection deformation capacity.9. CGMRFS with properly designed and detailed RBS connections is a reliable system to resist earthquakes.AcknowledgementsStructural Design Engineers, Inc. of San Francisco financially supported the experimental program. The tests were performedin the Large Scale Structures Laboratory of the University of Nevada, Reno. The participation of Elizabeth Ware, Adrianne Dietrich and of the technical staff is gratefully acknowledged.References受弯钢框架结点在变化轴向荷载和侧向位移的作用下的周期性行为摘要这篇论文讨论的是在变化的轴向荷载和侧向位移的作用下，接受测试的四种受弯钢结点的周期性行为。

xxxxxx大学本科毕业设计外文翻译Project Cost Control: the Way it Works工程本钱控制：它的工作方式学院〔系〕：xxxxxxxxxxxx专业：xxxxxxxx学生姓名：xxxxx学号：xxxxxxxxxx指导教师：xxxxxx评阅教师：完成日期：xxxx大学工程本钱控制：它的工作方式在最近的一次咨询任务中，我们意识到对于整个工程本钱控制体系是如何设置和应用的，仍有一些缺乏理解。

所以我们决定描述它是如何工作的。

理论上，工程本钱控制不是很难跟随。

首先，建立一组参考基线。

然后，随着工作的深入，监控工作，分析研究结果，预测最终结果并比拟参考基准。

如果最终的结果不令人满意，那么你要对正在进展的工作进展必要的调整，并在适宜的时间间隔重复。

如果最终的结果确实不符合基线方案，你可能不得不改变方案。

更有可能的是，会 (或已经) 有围变更来改变参考基线，这意味着每次出现这种情况你必须改变基线方案。

但在实践中，工程本钱控制要困难得多，通过工程数量无法控制本钱也证明了这一点。

正如我们将看到的，它还需要大量的工作，我们不妨从一开场启用它。

所以，要跟随工程本钱控制在整个工程的生命周期。

同时，我们会利用这一时机来指出几个重要文件的适当的地方。

其中包括商业案例，请求〔资本〕拨款〔执行〕，工作包和工作分解构造，工程章程(或摘要)，工程预算或本钱方案、挣值和本钱基线。

所有这些有助于提高这个组织的有效地控制工程本钱的能力。

业务用例和应用程序(执行)的资金重要的是要注意，当负责的管理者对于工程应如何通过工程生命周期展开有很好的理解时，工程本钱控制才是最有效的。

这意味着他们在主要阶段的关键决策点之间行使职责。

他们还必须识别工程风险管理的重要性，至少可以确定并方案阻止最明显的潜在风险事件。

在工程的概念阶段•每个工程始于确定的时机或需要的人。

通常是有着重要性和影响力的人，如果工程继续，这个人往往成为工程的赞助。