土木工程专业英语论文设计

关于土木工程英语作文英文回答：Civil engineering is a broad and challenging field that encompasses the design, construction, and maintenance of the built environment. As a civil engineer, I have the privilege of working on a wide range of projects, from bridges and roads to buildings and water treatment plants.One of the most rewarding aspects of civil engineering is the opportunity to make a tangible difference in the world. The structures that we design and build have adirect impact on the lives of people and communities. For example, a new bridge can connect isolated areas, a new road can improve access to essential services, and a new building can provide shelter and comfort for those who need it.Another aspect of civil engineering that I find particularly interesting is the challenge of constantlyinnovating. The field is constantly evolving, and new technologies and materials are emerging all the time. This means that civil engineers must be adaptable and willing to learn new things.Of course, civil engineering is not without its challenges. One of the biggest challenges is the need to balance the competing demands of safety, cost, and sustainability. Civil engineers must be able to design structures that are safe and reliable, but they must also be mindful of the cost of construction and the environmental impact of the materials used.Another challenge is the need to work with a variety of stakeholders, including clients, architects, contractors, and government agencies. Civil engineers must be able to communicate effectively with all of these stakeholders to ensure that the project is completed successfully.Despite the challenges, civil engineering is a rewarding and fulfilling career. I am proud to be a part of a profession that makes a real difference in the world.中文回答：土木工程是一个既广泛又富有挑战性的领域，涵盖了建造环境的设计、建造和维护。

2012-2013学年第二学期专业英语考试论文姓名学号院系土木工程与建筑系专业土木工程年级 10级任课教师2013年6月16日The Current Status and Future Developing Trend of CivilEngineering土木工程的发展现状与未来发展趋势IntroductionCivil Engineering English is Civil Engineering, literal translation is the civil engineering, it is referred to as the construction of the project. It means building objects, namely the construction on the ground, underground, water engineering facilities, equipment and materials to use in the survey, design and construction, maintenance, repair and other professional technology. From the history of civil engineering development, enhance the development of the use of design theory, every new building materials and construction technology for civil engineering will bring leap - style development. Therefore, from twenty-first Century to today with the human, with the promotion and development of the design theory of use, new building materials and construction technology, today's civil engineering has undergone important changes.Civil engineering is the construction of various types of Engineering Science and technology. It refers to the application of materials, equipment and carried out the survey, design, construction, maintenance, repair and other technical activities; also refers to the construction of the object, that is built on the ground or underground, on land or in the water, directly or indirectly to human life, production, military, scientific research and service of various engineering facilities, for example housing, roads, railways, pipelines, tunnels, bridges, canals, dams, harbors, stations, airports, offshore platform, water supply and drainage and protection engineering.Abstract: the civil engineering can be said to be a kind of civilization, which produces along with the social production, the civil engineering has got certain development, civil engineering is the existing form of indispensable, the future life will be more vigorous development, in order to satisfy the people demand more.Keywords: civil engineering construction management of industrial and civil architecture engineering economy.摘要：土木工程可以说是一种文明，随着社会的产生而产生，当今的土木工程已经得到了一定的发展，土木工程是不可缺少的存在形式，未来的生活中更会得到大力的发展，以满足人们更多的需求。

Structural FormsStructural forms, such as the beam or the arch ,have developed through the ages in relation to the availability of materials and the technology of the time. The arch, for instance, undoubtedly developed as a result of the availability of brick. In the technology of buildings .every structure must work against gravity ,which tends to pull everything down to the ground .A balance must therefore be attained between the force of gravity ,the shape of the structure ,and the strength of the material used. To provide a cover over a sheltered space and permit openings in the walls that surround it ,builders have developed four techniques are post and lintel, arch and vault, truss, and cantilever construction.Post and lintel. In post and lintel construction ,a horizontal beam is placed across the space between two supporting posts. If the support is continuous, it is called a wall; if a series of beams are joined together into a continuous surface, it is called a slab.Simple rectilinear buildings result from post and lintel construction, which is characteristic of much primitive construction as well as of the classical Greek temples. In this type of construction, the post (or column) carries only a vertical weight, or load, and is therefore under compression, and the lintel (or beam) is bent by the loads acting transversely to its axis. Therefore , the post must have compressive strength, and the beam must have bending strength. Both wood and stone were used in early example of this type of construction , although the limited bending strength of stone dictated the close column spacing which is apparent in Greek temples. For example, in the Parthenon in Athens, the space between the columns is approximately equal to the column diameter.Modern building materials such as steel and reinforced concrete are used to advantage in post and lintel construction. The skeleton frame of a modern steel skyscraper, for instance, consists of beams and columns in a three-dimensional post and lintel network, or grid. The typical wood fame house, with closely spaced wooden post, or studs, and floors with a series of closely spaced wood beams, or joists, also illustrates post and lintel construction.Just as a house of cards can support vertical loads but collapses under a slightbreath of air, the post and lintel system can topple under winds or earthquakes, but of which impose a horizontal force. This collapse is due to the fact that the joint between the column and beam acts as if it were a hinge .In earlier times this lateral instability was not apparent because the weight and the mass of the materials (particularly stone) and the limited height of the structures negated the importance of horizontal forces. In tall modern building that have slender elements made of strong and light materials such as steel, lateral instability becomes a significant factor . To provide the necessary lateral resistance, a rigid connection must be made between the vertical column and horizontal beam. This creates a rigid frame; it is used to achieve lateral stability in skyscraper construction.Arch. The arch which is characteristically a masonry type of construction, undoubtedly had its origin in Mesopotamia，a land of brick buildings. Arches consist of masonry blocks in the form of a curved line. In principle, each wedge-shaped masonry block cannot fall inward without pushing the others out ;thus, the whole arch form remains stable as long as a force is applied at the base to keep it from spreading. This force is called a horizontal thrust. A continuous series of arches is known as a vault.The Etruscans, by their examples of arch constructions in bridges and gates, probably inspired the Roman to experiment with this type of construction about 600 B.C. However, it was not until the last years of the Roman republic that tunnel vaults and intersecting, or groined, vaults were used to cover large rooms. The form of the Roman arch or vault is generally semicircular for reasons of geometric simplicity. As a result, all wedge-shaped stones are identical; their curved edges are equidistant from the center of the circle ,and their straight edges lie on equally spaced lines radiating from the center. This type of semicircular arch was widely used by the Romans in buildings such as the Basilica of Constantine and the Baths of Caracalla and in gates such as the Porta Maggiore in Rome.The Gothic arch, which is characterized by its pointed shape ,evolved in France in the 12th century. This form characterizes some of the most magnificent churches of the early Renaissance period such as the Chartres. Amiens, and Rheims cathedral. theform of the Gothic arch is superior to the Roman arch because of its greater structural clarity, which closely approaches the shapes the shape of an idea arch. The concept of the idea arch can best be explained by a comparison with a suspension cable.A chain or a cable supported at each end assumes a curved shape called a catenary (from catena, chain).If the cable were required to support one weight hung from it ,it would change shape to adjust to this condition ;this is due to the fact that a cable carries loads only by the actin of simple tension along the length of the cable. If, instead of a single load, many parabola. The catenary and the parabola are geomertrically similar since the weight of the cable is approximately a uniformly distributed load .An ideal arch may be thought of as a cable frozen in its shape and turned upside down.(Instead of carrying loads by tension, as in the cable, the ideal arch carries loads by simple compression)This ideal shape of load the arch is called the “funicular curve” A different funicular curve exists for every type of load the arch is required to carry. Since the arch ,unlike the flexible cable ,cannot adjust its shape to the load ,then the arch, under a load other than that which gave it its funicular shape, must also carry the load by bending, as in a beam .The structural efficiency of an arch can thus be measured in terms of the proximity of the geometric shape to the funicular curve ,In the semicircular Romans arch ,there is a large difference between the funicular curve of the loads and the circular shape. The pointed Gothic arches are much closer to the funicular curve of the loads and therefore possess a clear advantage over the earlier semicircular form.To resist the horizontal thrust which exists at the base of an arch ,the Roman used massive piers or buttresses. In some of the Gothic cathedrals, which raised the arch high above the nave, flying buttresses over the side aisles were used to counteract the thrust.In modern times ,arch construction has been used extensively for bridge, utilizing steel, wood, or reinforced concrete. The concrete arch bridges built by Robert Maillart in Switzerland are outstanding examples of elegance and structural clarity in modern arch design.Truss. The simplest form of truss is a triangle consisting of three bars. Thiselementary truss form undoubtedly grew out of the use of the gabled roof for small houses and churches. In this construction, two slanting rafters rest on top of a wall and are pinned at the peak. The load of the roof tends to push out the top of the walls. Tying the bottom of the rafters together with a bar or rod counters this outward push. The resulting triangular shape is a rigid form geometrically, because none of its angles can change without changing the length of its sides. Each element in a truss is subject to either tension or compression; in the simple triangular truss, the rafters are in compression and the tie rod is in tension.The elementary triangular truss is limited to spanning relatively short distance because each slanting member is long compared to the span. In a triangular truss with equal angles, for instance, each member is as long as the span. This drawback was recognized by Andrea Palladio in the 16th century. His design for a trussed bridge utilized the principle that if a single triangles is rigid ,combinations of triangles are also rigid . By arranging short lengths of timbers in a series of triangles to form complex trusses, almost any distance can be spanned.It was not until the 19th century , when mathematical methods of analysis became known and iron and steel were introduced, that trusses with a great degree of perfection and elegance were developed. Modern trusses with a variety of configurations are used to span auditoriums, armories, and convention halls , creating large column-free spaces. The type of trusses most commonly used in buildings are the Pratt, Howe, and Warren trusses, all named after their inventors. The Pratt and Howe trusses have top and bottom chords (horizontal elements), and both verticals and diagonals between the chords. The Warren truss has only diagonals joining the top and bottom chord .Cantilever. In cantilever construction, building elements are projected outward from a fixed support. An early kind of cantilever construction was the corbel; it had its origin in the late Stone Age and can be found in the form of corbelled domes built in Sarrdinia about 2,500 B.C. In corbel construction, each successive layer of stone stands out farther from a wall in the form of upside-down steps. Only the weight of the stones above and behind the face of the wall prevent a corbel from collapsing. Anexcessive amount of material is required for corbel construction because of the necessity for heavy masonry walls.Cantilevering building elements from a wall or other fixed support permits projecting part of a building beyond the ground-level construction to gain more living area above, as in many of the Renaissance town houses.The cantilever is much used in modern buildings as a result of the availability of steel and reinforced concrete. It is a simple matter in a concrete apartment building to create a cantilevered balcony when the balcony slab is merely a continuation of the interior slab. The Kaumfman house, built by Frank Lloyd Wright in 1939, is an example of a dramatic use of cantilevers and demonstrates the potential of this type of construction. In a steel-framed building, beams can project beyond column to permit the face of the building to be a curtain wall with large glass areas. This cantilever construction was exemplified by the Bauhaus (1926) ,which was used as a model for many skyscrapers built after World WarⅡ结构形式结构形式，如梁或拱，通过发展有关的材料供应和当时的技术的年龄。

土木工程英语论文Building drainage of water-saving techniquesWith people's quality of life?the quality and quantity of wa ter areconstantly expanding. Implement sustainable water use and prot ection of water resources from destruction. And access to he althy water, recycling of water, has become the government a nd the broad masses of the people the focus of attention. All this gave to the construction of drainage works on the design of the many new requirements, water supply advanced technology of the urgent need to accelerate the pace. This paper willexplore more of the building for drainage of water-saving te chnology; we hope to arouse the awareness of water conservat ion to build water-saving city efforts.Construction of a water-saving project, in addition to the w ater saving should formulate laws and regulations to strength en the management and day-to-day publicity and education use price leverage to promote water conservation work, but also take effective measures, to ensure that the construction of water-saving work carried out in-depth andcomprehensive. We are aware that the water supply network's coverage, the extension oftransmission mains and the construction of the building becau se arising from the difference in height, will be used to increase the water pressure before the end of ways to prote ct the most disadvantaged water points will be adequate wate r supply, This will be a large number of regional supply o f high pressure water supply is. Therefore accessories before the water hydrostatic head greater than outflow, the flow was greater than the rated flow capacity. Beyond the rated flow capacity of that part of the normal flow did not have the use efficiency is a waste of water. As a result of this water is being wasted is not easy to detect and under stand, it could be called a "stealth" wasting water.It has been in a different type of floor, the building 67 waterdistribution points so the overpressure from the measured flo w analysis, Statistical results are 55% of the iron spiral movements - taps(hereinafter referred to as "ordinary water") and 61% of the ceramic valve - leading the flow of water-saving more than their rated flow, thesuper-flow pressure from the state. Two endings the largest flow out of the rated flow capacity of about three times [ 1]. This shows that in ourexisting buildings, water supply system overpressure out-flow phenomenon is widespread and it is a fairly serious. In dis tribution point pressureAs overpressure flow out of the "invisible" water is not wa sted paid enough attention to, So in our existing "building water supply and drainagedesign" and "construction water supply and drainage design GB J15-20 00 draft "(hereinafter referred to as" draft "), alth ough the wateraccessories and home support the greatest pressure certain re stricprovisions in [2], but this is only to prevent water from the high pressure parts will lead to damage to the point o f consideration, not prevent excess pressure from the out-flo w point of view, the pressure is too lenientrestrictions on the flow overpressure no fundamental role. Th erefore, in accordance with the water supply system overpress ure flow from the actual situation, the pressure on the wat er supply system to make reasonable limit.1.2 measures taken decompressionWater supply system in a reasonable allocation of decompressi on device is to control pressure within the limits required to reduce excesspressure from the flow of technical support.1.2.1 Jangled nervesRelief valve is a good decompression device, can be divided intoproportional (lower left) of direct action and the type (Pho to) The former is based on the ratio of the area to deter mine the proportion ofdecompression, which can be set under pressure prior decompre ssion, When the water-stop water, you can also be controllin g the vacuum tube pressure is not increased, Decompression c an achieve dynamic can achieve static decompression.1.2.2 Decompression orifice and conserving Cypriots1106Orifice decompression compared with jangled nerves example, th e system is relatively simple, less investment, easy manageme nt. The practice of some units, water-saving effects are fai rly obvious, If Shanghai Jiao tong University in the school bathroom water pipe installation aperture of 5mm orifice, water-saving about 43%. But decompression orificeonly by the dynamic pressure, static pressure can be reduc ed and the pressuredownstream with the upstream pressure and the flow is change d, is not stable enough. In addition, the vacuum orifice pl ug easy. In better water quality and water pressure more st able, by using [3]. Cutting expenditure and the role of Cyp riot advantages and decompression orifice basically are the s ame. Suitable for the small diameter and accessories installed to use [3].1.3 adopt water-saving leadingA trial showed that the leading Practical water-saving taps and thegeneral state of the full, flow out of the former than the latter out ofthe flow. That is the same pressure, the leading water cons ervation hasgood water saving, water-saving volume in 20% ~ 30% between. And the higher the pressure ordinary tap water from the l arger, water-saving is leading the greater the volume of wat er-saving. Therefore, should the building (especially in the standard water pressure in water distribution points) leading installation of water-saving, reduce water wastage. In 1999 the Ministry of Construction, State Economic and Trade Comm ission, State Bureau of Building materials apparatuses jointly issued a document "on the elimination of residential buildi ngs behind the products notified"Tonyseasin 2016/5/25 8:08:50：require large and medium-sized cities in new residential proh ibit the use of helical-style cast iron nozzle movements, ac tively adopt "ceramiccartridge faucets" and "common faucet technical conditions of the ceramic cartridge faucets [4]. Since the main building of our school building earlier in the toilet faucet is st ill an ordinary spiral movement - iron taps. We have often seen leading loosening and tightening the leading difficulty caused by the leakage phenomenon. In fact, there is such afaucet overpressure caused by the "invisible" huge waste of water. Schools should arouse the concern of the relevant dep artments, from the long-term interests for the use of water-saving new leader, reduce unnecessary losses.2 vigorously develop the construction of water facilities, "w atercourse." As the name suggests is not delivered on the w aterways clean water is not sullied by sewage contamination. Residents put a wash, bathing, washing clothes and other w ater washing and flushing water together, after CO., filtrati on and disinfection, Sterilization, which imported waterway ne twork, for toilet flushing, washing cars, and pouring green, onto the road and other non-drinking purposes. China theref ore waterway is alsoknown as miscellaneous water Road. With a watercourse which cubic meters of water, equivalent to the use of one cubic meters of clean water, emit less nearly a cubic meter of s ewage and kill two birds with one stone.Water-saving achieved nearly 50% [3]. Therefore, the channel has many of the world's water shortage in cities used exten sively.2.1 full use washing wastewater and other quality miscellaneo us drainage The existing water facilities built in most hote ls, colleges, and thebasic source for the bathroom bathing wastewater. For some s mall units, smaller than bathing wastewater, and discharge ti me is too concentrated, Water facilities are not stable and adequate source of water. And washing with water wastewater , the use of time more evenly, water treatment and the adv antages of relatively good, as a water source, to be fully exploited.2.2 Develop and implement as soon as possible the return to the new water quality standardsThe current construction of water reused implementation of th e existing life miscellaneous water quality standards.? The t otal coli formstandards and the requirements of "sanitary standard for drin king water," the same, compared to the developed countries a nd the Chinese water standards apply to the swim-minus III also strict standards. This has led to two problems: First, many of the existing water works is less than the standar d; 2 are fulfilled with a certain degree of difficulty, imp rove the water project investment and processing cost. So sh ould developappropriate indicators of the value of water works to promot e the spread and popularize. Water Saving water is not limi ting, or even prevents the water. But reasonable people to water, efficient use of water and not waste.8:09:15Tonyseasin 2016/5/25 8:09:15预览：As long as we pay attention to fit the family's bad habits , we will be able to water-saving around 70% [3]. Water an d waste a lot of the habits, such as: flush toilets single wash cigarette butts and broken fine waste; to access a c up of cold water. Many people will not venting water; spend the potatoes, carrots after peeling, washing or after the optionalvegetables; when the water stopped (open access customers, an swer the phone, change TV channels), not turning off the ta p; During the suspension, forget turning off the tap; toilet s, wash, brush, let the water has been flowing; Before slee p, go out, do not check the faucet; equipment leaks, not p romptly repaired. From the following table, we can see in m any parts of life as long as we interested to note that t he conservation of water is very impressive.3 to promote the use of water-saving devicesIn addition to the family of water-saving attention to culti vate good habits of water, using water-saving devices is ver y important and also the most effective. Some people prefer laissez-faire, but also refused to replace water-saving devi ces, in fact, so much water is a long timedown the uneconomical. Thus vigorously promote the use of wa ter-saving devices is the construction of water-saving importa nt ways and means.3.1Water-saving taps3.1.1 Water Saving leading CeramicsCurrently most of the water-saving taps used Ceramics taps. Such tapscompared with ordinary taps, water was typically up to 20% ~ 30%; and other types of water-saving compared to the lead ing and cheap [3]. Therefore, in the residential buildings o f architectural vigorously promote the use of such water-savi ng lead. We taught the fifth floor of the dormitory building and are used by such leading.3.1.2 Closed since delay tapsSince the delay in the water taps closed after a certain t ime, shut down automatically to avoid Changliushui phenomenon. Water timing to be in a certain range adjustment, both fo r the convenience of Health has complied with the water-savi ng requirements suitable for washing in public places with.3.1.3 Photoelectric controlled tapsClosed since the delay of water-saving taps but water while fixed time and meet the different requirements of the use of the object.Photoelectric controlled taps will be able to overcome the a bove drawbacks, such as the latest one of the type of infr ared device control wash, The first installation will be sel f-inspection of the device in front of or below the fixed reflectors (for example, vanity) and based on thereflectors adjust their distance from work to avoid the past because of automatic water obstacles closer to the front o f regular water, Such intelligent device can wash your hands although below action without washing their hands without w ater. a long time will wash water and do notTonyseasin 2016/5/25 8:09:49预览：have long-term can also regularly flush Water Seal failure t o avoid a supply shortage ahead of the police [3].3.2The total water-saving flush3.2.1 Use of small volume cisterns commodeChina is promoting the use of water tanks 6 L fecal water-saving devices, and have flushing water to 4.5 L or even l ess, stood on the stool available. However, we should also pay attention to the drainage system to ensure the normal w ork of the use of small volume cisterns commode, otherwise they will be brought to plug the pipeline, not a net wash, and other issues. Two respectively flushing cisterns in uri ne, flushing water for 4 L (or less); Washing stool, Chong stood at 9 L (or less) [3]. (Map is a two-valve I-Yuan annually to the water tanks, to open the stool below the d rain urine when opened above the drain Pictured left is the two-block cisterns switch several forms) Israel's constructio n regulations require all newbuildings to install two respectively wash cisterns. China sh ould also vigorously promoted two respectively cisterns, becau se one day, the number is far higher than the urine stool frequency. To three homes as an example, per person per d ay for a meeting of feces, urine four times and the use o f existing water tanks L 9, day to 135 L of water; 6 L of water use, 90 L of water a day;and the use of cisterns two respectively, 75 L of water a day, can be seen using two respectively cisterns 9 L 6 L than using more water-saving cisterns [3]. 6 L Yuan annually to the use of water-saving cisterns better results. The use of tanks in two trances another advantage is not right and the replacement of the total drainage system to carry out reform therefore particularly applicable to existing bui ldings the total replacement of water tanks.3.2.2-washing UrinalThe United States launched the Urinal-washing, which is not water, the stench from the toilets without using utensils, I n fact, only in one end Urinal add special "trap" devices, but because the economic, health, water effectively, So pop ular station.3.2.3Photoelectric control UrinalUrinal photoelectric controls in a number of public buildings installations.3.2.4 Delayed flushing valve closedIt is the use of guide-work principle, water officials direc tly connected with the water pressure high enough circumstanc es, can protect theinstantaneous flushing commode needs to replace tanks and acc essories, installation is simple and easy to use, health, lo w prices, Water-saving effect of the obvious characteristics [3]. We carpentry center is used for such cleaning.3.3 in hot water systems installed in various forms of wate r-saving devicesTonyseasin 2016/5/25 8:10:24预览：If installed in public bathrooms limited flow orifice, in th e cold, hot water imported pressure balance between the inst allation of equipment; Installation of low-flow plumbing. Infl atable hot water thermostat and cooling, hot water mixed hyd rants.3.4 to further develop various forms of water-saving devices 3.4.1 Development of different water taps outSome countries, in different places with different water out of taps,Singapore provides water for washing vegetables pots 6 L / min, shower water 9 L / min; China's Taiwan Province launch ed the spray-wash special taps, the flow was 1 L / min. I n China, various taps most of the rated flow capacity of 0 .2 L / s, that is 12 L / min, excessive [4]. Therefore b e reasonable to develop taps the rated flow, and gradually installed in different places different from water taps.3.4.2 Vacuum water-saving techniquesTo ensure that sanitary ware and sewer cleaning effect of v acuumtechnology can be applied to drainage works Most of the air instead of using water, relying on the vacuum of high-spee d gas-water mixture, and rapid disposal of the sewage, dirt-gully clean and save water and drain away the effects of d irty air. A complete vacuum drainage system,including: vacuum valve and with a magnitude of suction devi ces occupants, the closed aqueduct, vacuum collection containe rs. Vacuum pumps, control equipment and channels and so on. Together with the vacuum generated 40 ~ 5min the negative pressure of sewage pumped to the collection containers, the n will collect sewage pump effluent into the municipal sewer . Different types of construction in the use of vacuum tech nology, the average water-saving exceed 40%.。

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 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 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 crackbe 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 result that.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 actualengineering, work°out a problem acc ording to the actual circumstance.In the concrete engineering the familiar crack and the prevention1.StemSuo 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 plete 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.StemSuo 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.StemSuo 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 waterash of the concrete ratio, the dosage of the position, 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 acmodation 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 acmodation 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 centerthin 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, perhaps concrete just eventually Ning but strength very hour, be subjected to heat or pare 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 mon 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 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 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 adoptcertain 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 pare 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 creationcrack, 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 airtight.Crack width the size be different, be subjected to temperature variety influence more obvious, winter pare 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 e to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lowersprinkle 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 WenSheng, 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.14is 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 acmodation 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 ually ofprevent 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- Shenability.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 continueunder 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 knot the material harden behind and concrete formation one be whole, thus reinforce of purpose.The in mon 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 mon 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 mon use Su material has PVC gum mire, plastics ointment, the D Ji rubber etc.;In mon 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 mon 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 typesteel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete pensation 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 mon use displacement material have:mon 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 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 mon 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 position(such as contain to glue knot of the liquid Xin fiber or capsule) in the concrete of the tradition the position, 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》。

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 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 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。

帮我写一篇关于土木工程的英语作文English:Civil engineering is a discipline that plays a crucial role in shaping the world we live in today. It encompasses a wide range of activities, including the design, construction, and maintenance of infrastructure such as buildings, roads, bridges, airports, and water supply systems. Civil engineers are responsible for ensuring that these structures are safe, efficient, and sustainable. They use their expertise in mathematics, physics, and materials science to design structures that can withstand various environmental conditions and loads. Additionally, civil engineers play a significant role in addressing societal challenges such as urbanization, climate change, and resource scarcity by developing innovative solutions and implementing sustainable practices. Collaboration with architects, urban planners, environmental scientists, and policymakers is essential to ensure that civil engineering projects meet the needs of communities while minimizing environmental impact. Overall, civil engineering is a dynamic and rewarding field that combines technical knowledge with creativity and problem-solving skills to improve the quality of life for people around the world.中文翻译:土木工程是一个在塑造我们今天生活的世界中起着至关重要作用的学科。

土木工程专业英语考试重点|土木工程专业英语考试改革研究论文摘要:土木工程专业英语在土木工程高级专门人才培养中发挥着重要作用，而课程考试的命题内容、考核方式、评价标准等直接影响学生的学习态度、学习方式及学习习惯。

文章提出了土木工程英语考试命题思路、试题内容、考核方式和成绩评定方式等教学全过程控制的土木工程专业英语考试改革方法，将土木工程英语课程教学的整个过程作为考核学生学习效果的全过程，促进学生的最大化发展，为培养土木工程国际化高端人才奠定坚实的基础。

关键词:专业英语;全过程控制;创新体系随着科学技术的进步和工程实践的发展，土木工程学科已发展成为内涵广泛、结构复杂的综合体系，相应的土木工程技术和相关的理论也应运而生。

同时，随着国际化分工的日益细化，我国越来越多的设计企业、施工管理企业走出国门进行土木工程建设活动，一些大型基础设施项目的设计方案、施工等均通过国际招投标进行。

这些变化对土木工程专业技术人员的英语水平提出了更高的要求，迫切需要高校培养既精通专业知识又精通英语的土木工程国际化高端人才［1－3］。

为全面提高学生的土木工程专业英语综合应用能力，文章基于课程教学的全过程对土木工程专业英语考试进行一些新的尝试和改革，以期达到巩固知识、发展能力和提高素质的目的。

一、土木工程专业英语考试模式现状多年来，土木工程专业英语的教学效果不容乐观，考试模式单一，教学改革研究滞后于社会需求等诸多原因导致本科生甚至研究生写一篇300字的英文摘要都无从下笔，困难重重。

专业英语课程由专业课教师组织教学，课堂教学时间有限，考试模式单一，导致土木工程专业英语学习缺乏连续性、整体性和深入性，学生不具备学以致用的能力。

目前，土木工程专业英语课程仍然延续着传统的试卷考试形式。

课上教师讲授，课下完成教师布置的任务。

期末对基本原理和知识点掌握理解情况设置统一的卷面考试。

作业占成绩的20%，最后考试占成绩的80%。

这种考试模式过于古板，没有完全发挥学生的主观能动性，不利于学生消化课堂所学知识，仅限于纸上谈兵。

Structure of BulidingsA building is closely bound up with people, for it provides people with the necessary space to work and live in. As classified by their use, buildings are mainly of two types: industrial buildings and civil buildings. Industrial buildings are used by various factories or industrial production while civil buildings are those that are used by people for dwelling, employment, education and other social activities.The construction of industrial buildings is the same as that of civil buildings. However, industrial and civil buildings differ in the material used, and in the structure forms or systems they are used.Considering only the engineering essentials, the structure of a building can be difined as the assemblage of those parts which exist for the purpose of maintaining shape and stability. Is primy purpose is to resist any loads applied to the building and to transmit those to the ground.In terms of architecture, the structue of a building is and dose much more than that. It is an inseparable part of the building form to varying degrees is a generator of that form. Used skillfully, the building structure can establish or reinforce orders and rhythms among the architecture volumes and planes. It can be visually dominant or recessive. It can develop harmonies or conflicts. It can be both confining and emincipating. And, unfortunately in some cases, it cannot be ingored. It is physical.The structure must also be engineered to maintain the architecture form. The principles and tools of physics teand mathematics provide the basis for differentiating between rational and inrational forms in terms of construction. Artists can sometimes generate shapes that obviate any consideration of science, but architects cannot.There are at least three items that must be present in the structure of a building: stabily, strength and stiffness, economy.Taking the first of the three requiements, it is obvious that stability is needed to maintain shape. An unstable building structure implies unbalanced forces or a lack of equilibrium and a consequent acceleration of the structure or its pieces.The requirement of strength means that the materials selected to resist the stresses generated by the loads and shapes of the structure(s) must be adequate. Indeed, a “factor of safety” is usually provided so that under the anticipated loads, a given material is not stressed to a level even close to its rupture point. The material property called stiffness is considered with the requirement of strength. Stiffness is different form strength in that it directly involves how much a structure strains or deflects under load. A material that is very strong but lacking in stiffness will deform too much to be of value in resisting the forces applied.Economy of a building structure refers to more than just the cost of the material used. Construction economy is a complicated subjectinvovling raw materials, fabrication, erection, and maintenance. Design and construction labor costs and the costs of energy consumption money(interest) are consumption must be consiedered. Speed of construction and the cost of money(interest) are also factors. In most design situations, more than one structural material requires consideration. Completive alternatives almost always exist, and the choice is seldom obvious.Apart form these three primary requirements, several other factors are worthy of emphasis. First, the structure or suctructural system must relate to the building’s function. It should not be in conflict in terms of form. For example, a linear function demands a linear structure, and therefore it would be improper to roof a bowling alley with a dome. Similarly, a theater must have large, unobstructed spans but a fine restaurant probably should not. Stated simply, the structure must be appropriate to the function it is to shelter.Second, the structure must be fire-resistant. It is obvious that the structural system must be able to maintain its integrity at least until the occupuants are safely out. Building codes specify the number of hours for which certain parts of a building must resist the heat without collapse. The structural materials used for those elements must be inherently fire-resistant or be adequently protected by fireproofing materials. The degree of fire resistance to be provided will depend upon a number ofitems, including the use and occupancy load of the space, its dimensions, and the location of the building.Third, the structure should integrate well with the building’s circulation systems. It should not be in conflict with the piping systems for water and waste, the ducting systems for air, or (most important) the movement of people. It is obvious that the various building systems must be coordinated as the design progresses. One can design in a sequential step-by-step manner within any one system, but the design of all of them should move in a parallel manner toward completion. Spatially, all the various parts of a building are interdependent.Fourth, the structure must be psychologically safe as well as physically safe. A highrise frame that sways considerably in the wind might not actually be dangerous but may make the building uninhabitable just the same. Ligheweight floor systems that are too “bouncy” can make the users very uncomfortable. Large glass windows, uninterrupted by dividing motions, can bu quite safe but will appear very insecure to the occupant standing next to on 40 floors above the street.Sometimes the architect must make deliberate attempts to increase the apparent strength or solidness of the structure. This apparent safety may be more important than honestly expressing the building’s structure, because the untrained viewer cannot distinguish between real and perceived safety.The building designer needs to understand the behavior of physical structures under load. An ability to intuit or “feel” structural behavior is possessed by those having much experience involving structural analysis, both qualitative and quantitative. The consequent knowledge of how forces, stresses, and deformations build up in different materials and shapes is vital to development of this “sense”.Structural analysis is the process of determining the forces and deformations in structures due to specified loads so that the structure can be designed rationally, and so that the state of safety of existing structures can be checked.In the design of structures, it is necessary to start with a concept leading to a configuration which can then be analyzed. This is done to members can be sized and the needed reinforcing determined, in order to: a) carry the design loads without distress or excessive deformations ( serviceability or working condition); and b) to prevent collapse before a specified overload has been placed on the structure (safety or ultimate condition).Since normally elastic conditions will prevail under working loads, a structural theory based on the assumptions of elastic behavior is appropriate for determining serviceability conditions. Collapse of a structure will usually occur only long after the elastic range of the materials has been exceeded at circal points, so that an ultimate strengththeory based on the inelastic behavior of the material is necessary for a rational determination of the safety of a structure against collapse. Neverthelese, an elastic theory can be used to determine a safe approximation to the strength of ductile structures (the lower bound approach of plasticity), and this approach is customarily followed in reinforced concrete practice. For this reasion only the elastic theory of gtructure is pursued in this chapter.Looked at critically, all structures are assemblies of three-dimensional elements, the exact analysis of which is a forbdding task even under ideal conditions and impossible to contemplate under conditions of professional practice. For this reason, an important part of the analyst’s work is the simplification of the actual structure and loading conditions to a model which is susceptible to rational analysis.Thus, a structural framing system is decomposed into a slab and floor beams which in turn frame into girders carried by colums which transmit the loads to the foundations. Since traditional structural analysis has been unable to cope with the action of the slab, this has often been idealized into a system of strips acting as beams. A lso, long-hand methods have been unable to cope with three-dimensional framing systems, so that the entire structure has been modeled by a system of planner subassemblies, to be analyzed one at a time. The modern matrix-computer methods have revolutionized structural analysis bymaking it possible to analyze entrie systems, thus leading to more reliable predictions about the behavior of structures under loads.Actual loading conditions are also both difficult to determine and to express realistically, and must be simplified for purposes of analysis. Thus, traffic loads on a bridge structure, which are essentially both of dynamic and random nature, are usually idealized into statically moving standard trucks, or distributed loads, intended to simulate the most severe loading conditions occurring in practice.Similary, continuous beams are sometimes reduced to simple beams, rigid joints to pin-joints, fillers-walls are neglected, shear walls considered as beams; in deciding how to model a structure so as to make it reasonably realistic but at the same time reasonably simple, the analyst must remember that each such idealization will make the soulation more suspect. The more realistic the analysis, the greater will be the confidence which it inspires, and the smaller may be the safety factor ( or factor of ignorance ). Thus, unless code provisions control, the engineer must evaluate the extra expense of a thorough analysis as compared to possible savings in the structure.The most important use of structure analysis is as a tool in structural design. As such, it will usually be a part of a trial-and-error procedure, in which an assumed configuration with assumed dead loads is analyzed, and the members designed in accordance with the results of theanalysis. This phase is called the preliminary design; since this design is still subject to change, usually a crude, fast analysis method is adequate. At this stage, the cost of the structure is estimated, loads and member properties are revised, and the design is checked for possible improvements. The changes are now incorporated in the structure, a more refined analysis is performed, and the member design is revised. This project is carried to convergence, the rapidity of which will depend on the capability of the designer. It is clear that a variety of analysis methods, ranging from “ quick and dirty to exact ”, is needed for design purposes.An efficient analyst must thus be in command of the rigorous methods of analysis, must be able to reduce these to shortcut methods by appropriate assumptions, and must be aware of available design and analysis aids, as well as simplification permitted by applicable building codes. An up-to-date analyst must likewise be versed in the bases of matrix structural analysis and its use in digital computers as well as in the use of available analysis programs or software.建筑结构建筑物与人类有着密切的关系，它能为人们在其中工作和生活提供必要的空间。

Buried tunnel project on the environmentAbstract: a deeply buried tunnel far-reaching impact on the environment through the waterways with the sinking pipe related. Under the tunnel on the mainland in the region and the impact of surface water in the tunnel design and construction method of choice to play the most important role. In considering the impact of the recent construction of a problem is the need to trench excavation for the tunnel may appear to be contaminated soil. And transporting the excavated soil up to the specialized equipment in order to receive their storage place is a series of important new technologies and quality control measures for environmental problems. The most common is in any construction project will encounter environmental problems, namely, noise, dust and traffic congestion. In this paper, these issues and the current technology to address these issues and measures are discussed.Key words: tunnel environmentCharacteristics of a Buried deeply buried tunnel tunnel has two fundamental characteristics: (1) It is part of an underground structure of the site, to ensure that heavy traffic conditions, construction, and does not mean that this area is full use of The. Therefore, the construction space is very valuable.Will eventually be installed in the location of the river or canal bottom section of tunnel is very close in other areas to build manufacturing plants, ways, and this condition is unlikely in the field and reached the site. The advantages of planning and construction of pipe manufacture and the site will be ready to separate from the logistical advantages are obvious, there are extremely easy to implement effective quality control advantages.Tunnel work site on the environmental impact is also considerablyless than the construction of the tunnel fully all the circumstances at the scene; such as space requirements and construction of transport, these two issues is greatly easing.Of course, a prerequisite for these benefits is a ready-made for pipe suitable site. It must meet the conditions for a series of environmental impact. In the Netherlands such as densely populated countries, to find a suitable site is not easy, but it is clear that once selected an available position, can be used repeatedly for quite a draw a crowd. Therefore, the overall plan for the tunnel construction is a common topic for discussion.Both ends of the structure of a new underground tunnel link to the original structure to the existing underground, often in fact across the waters to replace an existing facility, such as ferry or bridge. It can also be a complement existing facilities in tunnels or bridges. Whether the decision to build a new tunnel the reason, its location will be in large part by the constraints of existing underground structure layout, and its construction design must also meet the existing transport only by the requirements of minimal interference. This means that the location in the tunnel area designers rarely have a choice, and thus have the position according to the established conditions and requirements to modify the tunnel design.This situation mainly affects the approach roads connecting part of the tunnel itself. However, because the approach road through the water by the formation of sub-components, it may require new measures to control the approaches to the scope of the construction pit drainage impact.Buried Tunnel approach roads are almost always located in the deposition zone, where the tunnel approach road down to the groundwater level below. At its completion, they are impervious structure, the surrounding water can not penetrate, there's just the nature of the environmental impact of a simple structure.However, during construction, environmental issues will play an important role. To build from the structures, construction of foundation must be excavated until the water table following a number of meters deep,the traditional construction method requires the construction period in the continuous draining of the water. Unless further measures, or drainage will definitely lower the water level in the surrounding area, and will lead to a series of undesirable consequences. Subsidence will occur, based on the surrounding buildings and structures will be affected, and even deep pile foundation soil settlement will also be passed by the friction down to the pile on the extra load. Subsidence and elevation of the dam sinking, and agricultural drainage water will be affected.May also result in a completely different nature of environmental problems: the construction area may be contaminated soil. In this case, the construction of the excavation pit special attention to requirements and, if possible, should be used, such as soil mixed with water and water transport by pipeline, special methods. There must also be able to accommodate an approved place of contaminated soil.Number of measures must be taken to prevent the pumping of contaminated water caused by the rapid distribution of the soil to a large area on the ground.Technically speaking, is always possible to eliminate the impact of these kinds. However, it is extremely complex and do take a lot of money and time, therefore, tend to look at present the greatest extent possible the construction of approach roads and tunnels in the water imported methods. Ideally, the empty pit in the construction of a drainage of water should be no impact on the approach roads and the surrounding groundwater single operation.The obvious conclusion is that as far as possible the construction pit designed as part of the final product.Approach a wall can be designed to image the wall of the dam impervious core in the form of a slurry wall, curtain or plastic sheet of steel sheet pile walls common. On the final form (steel sheet pile wall) (off panel through the use of heavy anchor piles and soil) to increase its retaining function, you can save valuable space and can be easily achieved in the water and impermeable floor connection.Water under the concrete floor can be built. This approach hasbeen developed to control the elevation and surface roughness, which completely drained to the approach road after finishing requires less work.Another method is the use of impermeable plastic sheet, add water to the town of emphasis placed on the bottom and cover the pit slope. In the Netherlands, this approach not only for the tunnel approaches, and the groove for the public network segment.Use large plastic sheet, to the soil to the water for the town re-placed by a major highway intersection in the play a long-term good results, it shows that this technology has been widely used. Soon, the Netherlands, the tunnel approach roads may be to show a lush green slope, thereby replacing the gray concrete vertical wall.Approach can also be prefabricated elsewhere and in the form of installation of floating structures. This method only with trench excavation and dredging vessels do not have to drain. But not yet able to adequately address basic problems of buoyancy and appropriate design. Buried tunnel project on the environmentPipe manufacturing approaches to the excavation of underground water and the discussion of the relationship between the way the majority can be used to produce the same pipe excavation of the temporary venues. Expensive solution to bring an unreasonable burden to the project. Moreover, the manufacture of pipe near the site have repeatedly flooded the open waters and open to the precast tunnel segments into the transportation to the dock at the other pipe section in order to make room. Rarely a large enough place for all of the pipe manufacturer.In short, the choice of the location of manufacturing pipe dock not chosen as the location of the tunnel approach roads to be strictly determined by functional requirements, so choose the location of manufacturing pipe dock with the advantages of flexibility. Therefore, the manufacture of docks will be allowed to use the traditional water method, if the reasons listed above that do not allow the use of traditional water law, and the dock had to separate from the surrounding water, this places impermeable plastic plate because of its low cost to have obvious advantages.Another does not affect the drainage around the water table is "pumping recharge Law" This law is the foundation of the water into the pump discharge and pump water through the filter of these tube wells to the water source recharge area. As long as the penetration rate is not too large and can be maintained roughly a constant, the row, when the closed-loop irrigation can be maintained. The new measures, now being expanded in the Netherlands approaches to the construction of a pit, but also because the foundation of the dock as the manufacture of pipe it to be expanded.Construction of foundation trench trough structure deeply buried tunnel excavation method is dredging. In this paper, we only stress the importance of dredging requirements of foundation trench excavation method can achieve high accuracy, and this requires that the work will determine the most suitable type of device. Given the strict positioning tolerances, preferably dredging boat anchor or pile in positioning the dredging equipment. However, because they can not move freely, it could become an obstacle to shipping vessels.If there is water in the dredging area, or the wave of the impact of dredging will become the base slot to carry water along the bottom or sediment accumulation over the place. If the foundation trench excavation in place pipe for long periods, it will soon form a deposition. In these circumstances, the base section of tank excavation and tunnel installation of the interval between the two processes must be as short as possible, and thus the arrangement of the two procedure are to be particularly accurate, you can use a special device to clean the base before the installation of pipe slot. In the Netherlands, this operation has been developed to be used in the East (Eastern Scheldt) anti-dam pier storm waves reach a very high precision installation.Dredging stir up the river sediments, resulting in a certain time a certain area of the water turbidity. Eventually become a suspended fine particles of these substances will spread out and gradually settle down again. Although this process had limited impact on the environment, and harmless, but in a certain range or the increasingly strong criticism.If you want to have dredged soil is contaminated, it is even more complicated, because in such conditions, the dredging operation will cause the spread of contamination. Dredging technology has now developed to the drain by using a special mud head to eliminate this effect. Under the floating boat by hanging curtains from the dredging area will be completely separated from the surrounding method may also reduce the spread of pollution.Further development in this regard we have taken note of the current, most waterways in the Netherlands contain contaminated bottom sediments have been very clear, so dredging the mud is bound to take some special environmental requirements.Currently, these requirements have not been unified to form, but made different for each specific project requirements. Hope that this delay in the development of key technologies of the chaos can be quickly resolved.According to the type and extent of contamination, contaminated soil can be divided into 1 to 4 classes. For dredging mud (including dredging process water in the process) and disposal are subject to strict restrictions by category; particular, 3 and 4 the soil must be isolated, and in possible to be purified.In the Rotterdam area, has built a store of these solid waste and other hazardous substances the center of the dump site. In addition, Type 4 is placed in temporary dredging spoil heap smaller point, let it be purified and then transferred to another isolated place repository. Place in the absence of such facilities to be established by dredging this dump sites. This measure is a clear need to do a lot of work.Transportation and installation of pipe work and dredging the shipping obstacles to transport and install pipe sections are brought about environmental problems. To open the pipe system and installation of marinas and docks to deepen the shallow waters between the points need to channel dredging operations. Some of the previous discussion about dredging also apply to this situation.The installation procedures in a particular area may involve theend of the tunnel-based clean-up slot. To make clean-up and installation of the two processes reduce to a minimum interval of time, placed in the pipe to its final position before the bottom of the sand filling has been successfully used to shoot clean water law section of the base tunnel. With a powerful water jet to remove the last layer of the sediment washed into the suspension, followed by water flow away.Left in the pipe manufacturing dock, anchored at the temporary terminal and leave the temporary pier, floating point and transported to the installation during installation are likely to hinder shipping. Only the last one caused by the shipping process will complete in the short term temporary interruption or partial interruption.In this respect, a deeply buried tunnel across a river and there are differences across a canal. In the latter case, the absence of flow effects to make the sinking and installation of pipe can be better controlled. The advantage of this control to allow the use of more deeply buried sections of the tunnel tube pipe unit, but it must be large enough to create dock.Therefore, in the Netherlands, in the past most deeply buried pipe unit length of the tunnel are varied between 100 ~ 150m, crossing the North Sea Canal between Amsterdam and the Trondheim area tunnel (Hemtunnel) project has also used the unit for up to 268m of pipe . Use a longer pipe unit reduces the number of installation, which will slow down the barriers to shipping.Buried pipe for the tunnel project, it seems to impede the shipping for the environment as a problem, but not a major problem.This process includes filling with sand filling pipe at the base, back to the filling tank, and, if necessary in the pipe at the top of the construction of a scour protection layer.Backfill material must be uncontaminated. Ship in the tunnel construction work will interfere with the above shipping. However, by using a pipe installed in the tunnel were part of the operation of equipment, we can reduce such problems, for example, through the tunnel at the bottom of the holes by pumping sand and water mixture to backfilling.This system has been successfully applied in the Netherlands.Tunnel operation and maintenance operations involving major environmental issue is ventilation.Cleaning and maintenance of the tunnel wall to obstruct the road vehicle operation, they must be in the appropriate period of time quickly. Smooth wall and good coating helps to clean the operating table, thus reducing the time limit traffic through the tunnel.Road construction must be done to minimize future maintenance.。

外文翻译班级：xxx学号：xxx姓名：xxx一、外文原文：Structural Systems to resist lateral loads Commonly Used structural SystemsWith loads measured in tens of thousands kips, there is little room in the design of high-rise buildings for excessively complex thoughts. Indeed, the better high-rise buildings carry the universal traits of simplicity of thought and clarity of expression.It does not follow that there is no room for grand thoughts. Indeed, it is with such grand thoughts that the new family of high-rise buildings has evolved. Perhaps more important, the new concepts of but a few years ago have become commonplace in today’ s technology.Omitting some concepts that are related strictly to the materials of construction, the most commonly used structural systems used in high-rise buildings can be categorized as follows:1.Moment-resisting frames.2.Braced frames, including eccentrically braced frames.3.Shear walls, including steel plate shear walls.4.Tube-in-tube structures.5.Core-interactive structures.6.Cellular or bundled-tube systems.Particularly with the recent trend toward more complex forms, but in response also to the need for increased stiffness to resist the forces from wind and earthquake, most high-rise buildings have structural systems built up of combinations of frames, braced bents, shear walls, and related systems. Further, for the taller buildings, the majorities are composed of interactive elements in three-dimensional arrays.The method of combining these elements is the very essence of the design process for high-rise buildings. These combinations need evolve in response to environmental, functional, and cost considerations so as to provide efficient structures that provoke the architectural development to new heights. This is not to say that imaginative structural design can create great architecture. To the contrary, many examples of fine architecture have been created with only moderate support from the structural engineer, while only fine structure, not great architecture, can be developed without the genius and the leadership of a talented architect. In any event, the best of both is needed to formulate a truly extraordinary design of a high-rise building.While comprehensive discussions of these seven systems are generally available in the literature, further discussion is warranted here .The essence of the design process is distributed throughout the discussion.Moment-Resisting FramesPerhaps the most commonly used system in low-to medium-rise buildings, the moment-resisting frame, is characterized by linear horizontal and vertical members connected essentially rigidly at their joints. Such frames are used as a stand-alone system or in combination with other systems so as to provide the needed resistance to horizontal loads. In the taller of high-rise buildings, the system is likely to be found inappropriate for a stand-alone system, this because of the difficulty in mobilizing sufficient stiffness under lateral forces.Analysis can be accomplished by STRESS, STRUDL, or a host of other appropriate computer programs; analysis by the so-called portal method of the cantilever method has no place in today’s technology.Because of the intrinsic flexibility of the column/girder intersection, and because preliminary designs should aim to highlight weaknesses of systems, it is not unusual to use center-to-center dimensions for the frame in the preliminary analysis. Of course, in the latter phases of design, a realistic appraisal in-joint deformation is essential.Braced Frame sThe braced frame, intrinsically stiffer than the moment –resisting frame, finds also greater application to higher-rise buildings. The system is characterized by linear horizontal, vertical, and diagonal members, connected simply or rigidly at their joints. It is used commonly inconjunction with other systems for taller buildings and as a stand-alone system in low-to medium-rise buildings.While the use of structural steel in braced frames is common, concrete frames are more likely to be of the larger-scale variety.Of special interest in areas of high seismicity is the use of the eccentric braced frame.Again, analysis can be by STRESS, STRUDL, or any one of a series of two –or three dimensional analysis computer programs. And again, center-to-center dimensions are used commonly in the preliminary analysis. Shear wallsThe shear wall is yet another step forward along a progression of ever-stiffer structural systems. The system is characterized by relatively thin, generally but not always concrete elements that provide both structural strength and separation between building functions.In high-rise buildings, shear wall systems tend to have a relatively high aspect ratio, that is, their height tends to be large compared to their width. Lacking tension in the foundation system, any structural element is limited in its ability to resist overturning moment by the width of the system and by the gravity load supported by the element. Limited to a narrow overturning, One obvious use of the system, which does have the needed width, is in the exterior walls of building, where the requirement for windows is kept small.Structural steel shear walls, generally stiffened against buckling by a concrete overlay, have found application where shear loads are high. The system, intrinsically more economical than steel bracing, is particularly effective in carrying shear loads down through the taller floors in the areas immediately above grade. The system has the further advantage of having high ductility a feature of particular importance in areas of high seismicity.The analysis of shear wall systems is made complex because of the inevitable presence of large openings through these walls. Preliminary analysis can be by truss-analogy, by the finite element method, or by making use of a proprietary computer program designed to consider the interaction, or coupling, of shear walls.Framed or Braced TubesThe concept of the framed or braced or braced tube erupted into the technology with the IBM Building in Pittsburgh, but was followed immediately with the twin 110-story towers of the World Trade Center, New York and a number of other buildings .The system is characterized by three –dimensional frames, braced frames, or shear walls, forming a closed surface more or less cylindrical in nature, but of nearly any plan configuration. Because those columns that resist lateral forces are placed as far as possible from the cancroids of the system, the overall moment of inertia is increased and stiffness is very high.The analysis of tubular structures is done using three-dimensional concepts, or by two- dimensional analogy, where possible, whichever method is used, it must be capable of accounting for the effects of shear lag.The presence of shear lag, detected first in aircraft structures, is a serious limitation in the stiffness of framed tubes. The concept has limited recent applications of framed tubes to the shear of 60 stories. Designers have developed various techniques for reducing the effects of shear lag, most noticeably the use of belt trusses. This system finds application in buildings perhaps 40stories and higher. However, except for possible aesthetic considerations, belt trusses interfere with nearly every building function associated with the outside wall; the trusses are placed often at mechanical floors, mush to the disapproval of the designers of the mechanical systems. Nevertheless, as a cost-effective structural system, the belt truss works well and will likely find continued approval from designers. Numerous studies have sought to optimize the location of these trusses, with the optimum location very dependent on the number of trusses provided. Experience would indicate, however, that the location of these trusses is provided by the optimization of mechanical systems and by aesthetic considerations, as the economics of the structural system is not highly sensitive to belt truss location.Tube-in-Tube StructuresThe tubular framing system mobilizes every column in the exterior wallin resisting over-turning and shearing forces. The term‘tube-in-tube’is largely self-explanatory in that a second ring of columns, the ring surrounding the central service core of the building, is used as an inner framed or braced tube. The purpose of the second tube is to increase resistance to over turning and to increase lateral stiffness. The tubes need not be of the same character; that is, one tube could be framed, while the other could be braced.In considering this system, is important to understand clearly the difference between the shear and the flexural components of deflection, the terms being taken from beam analogy. In a framed tube, the shear component of deflection is associated with the bending deformation of columns and girders , the webs of the framed tube while the flexural component is associated with the axial shortening and lengthening of columns , the flanges of the framed tube. In a braced tube, the shear component of deflection is associated with the axial deformation of diagonals while the flexural component of deflection is associated with the axial shortening and lengthening of columns.Following beam analogy, if plane surfaces remain plane , the floor slabs,then axial stresses in the columns of the outer tube, being farther form the neutral axis, will be substantially larger than the axial stresses in the inner tube. However, in the tube-in-tube design, when optimized, the axial stresses in the inner ring of columns may be as high, or evenhigher, than the axial stresses in the outer ring. This seeming anomaly is associated with differences in the shearing component of stiffness between the two systems. This is easiest to under-stand where the inner tube is conceived as a braced , shear-stiff tube while the outer tube is conceived as a framed , shear-flexible tube.Core Interactive StructuresCore interactive structures are a special case of a tube-in-tube wherein the two tubes are coupled together with some form of three-dimensional space frame. Indeed, the system is used often wherein the shear stiffness of the outer tube is zero. The United States Steel Building, Pittsburgh, illustrates the system very well. Here, the inner tube is a braced frame, the outer tube has no shear stiffness, and the two systems are coupled if they were considered as systems passing in a straight line from the “hat” structure. Note that the exterior columns would be improperly modeled if they were considered as systems passing in a straight line from the “hat” to the foundations; these columns are perhaps 15% stiffer as they follow the elastic curve of the braced core. Note also that the axial forces associated with the lateral forces in the inner columns change from tension to compression over the height of the tube, with the inflection point at about 5/8 of the height of the tube. The outer columns, of course, carry the same axial force under lateral load for the full height of the columns because the columns because the shearstiffness of the system is close to zero.The space structures of outrigger girders or trusses, that connect the inner tube to the outer tube, are located often at several levels in the building. The AT&T headquarters is an example of an astonishing array of interactive elements:1.The structural system is 94 ft wide, 196ft long, and 601ft high.2.Two inner tubes are provided, each 31ft by 40 ft , centered 90 ft apartin the long direction of the building.3.The inner tubes are braced in the short direction, but with zero shearstiffness in the long direction.4.A single outer tube is supplied, which encircles the buildingperimeter.5.The outer tube is a moment-resisting frame, but with zero shearstiffness for the center50ft of each of the long sides.6.A space-truss hat structure is provided at the top of the building.7.A similar space truss is located near the bottom of the building8.The entire assembly is laterally supported at the base on twinsteel-plate tubes, because the shear stiffness of the outer tube goes to zero at the base of the building.Cellular structuresA classic example of a cellular structure is the Sears Tower, Chicago,a bundled tube structure of nine separate tubes. While the Sears Towercontains nine nearly identical tubes, the basic structural system has special application for buildings of irregular shape, as the several tubes need not be similar in plan shape, It is not uncommon that some of the individual tubes one of the strengths and one of the weaknesses of the system.This special weakness of this system, particularly in framed tubes, has to do with the concept of differential column shortening. The shortening of a column under load is given by the expression△=ΣfL/EFor buildings of 12 ft floor-to-floor distances and an average compressive stress of 15 ksi 138MPa, the shortening of a column under load is 15 1212/29,000 or per story. At 50 stories, the column will have shortened to in. 94mm less than its unstressed length. Where one cell of a bundled tube system is, say, 50stories high and an adjacent cell is, say, 100stories high, those columns near the boundary between .the two systems need to have this differential deflection reconciled.Major structural work has been found to be needed at such locations. In at least one building, the Rialto Project, Melbourne, the structural engineer found it necessary to vertically pre-stress the lower height columns so as to reconcile the differential deflections of columns in close proximity with the post-tensioning of the shorter column simulatingthe weight to be added on to adjacent, higher columns.二、原文翻译：抗侧向荷载的结构体系常用的结构体系若已测出荷载量达数千万磅重,那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了;确实,较好的高层建筑普遍具有构思简单、表现明晰的特点;这并不是说没有进行宏观构思的余地;实际上,正是因为有了这种宏观的构思,新奇的高层建筑体系才得以发展,可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了;如果忽略一些与建筑材料密切相关的概念不谈,高层建筑里最为常用的结构体系便可分为如下几类：1．抗弯矩框架;2．支撑框架,包括偏心支撑框架;3．剪力墙,包括钢板剪力墙;4．筒中框架;5．筒中筒结构;6．核心交互结构;7．框格体系或束筒体系;特别是由于最近趋向于更复杂的建筑形式,同时也需要增加刚度以抵抗几力和地震力,大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系;而且,就较高的建筑物而言,大多数都是由交互式构件组成三维陈列;将这些构件结合起来的方法正是高层建筑设计方法的本质;其结合方式需要在考虑环境、功能和费用后再发展,以便提供促使建筑发展达到新高度的有效结构;这并不是说富于想象力的结构设计就能够创造出伟大建筑;正相反,有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了,然而,如果没有天赋甚厚的建筑师的创造力的指导,那么,得以发展的就只能是好的结构,并非是伟大的建筑;无论如何,要想创造出高层建筑真正非凡的设计,两者都需要最好的;虽然在文献中通常可以见到有关这七种体系的全面性讨论,但是在这里还值得进一步讨论;设计方法的本质贯穿于整个讨论;设计方法的本质贯穿于整个讨论中;抗弯矩框架抗弯矩框架也许是低,中高度的建筑中常用的体系,它具有线性水平构件和垂直构件在接头处基本刚接之特点;这种框架用作独立的体系,或者和其他体系结合起来使用,以便提供所需要水平荷载抵抗力;对于较高的高层建筑,可能会发现该本系不宜作为独立体系,这是因为在侧向力的作用下难以调动足够的刚度;我们可以利用STRESS,STRUDL 或者其他大量合适的计算机程序进行结构分析;所谓的门架法分析或悬臂法分析在当今的技术中无一席之地,由于柱梁节点固有柔性,并且由于初步设计应该力求突出体系的弱点,所以在初析中使用框架的中心距尺寸设计是司空惯的;当然,在设计的后期阶段,实际地评价结点的变形很有必要;支撑框架支撑框架实际上刚度比抗弯矩框架强,在高层建筑中也得到更广泛的应用;这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色,它通常与其他体系共同用于较高的建筑,并且作为一种独立的体系用在低、中高度的建筑中;尤其引人关注的是,在强震区使用偏心支撑框架;此外,可以利用STRESS,STRUDL,或一系列二维或三维计算机分析程序中的任何一种进行结构分析;另外,初步分析中常用中心距尺寸;剪力墙剪力墙在加强结构体系刚性的发展过程中又前进了一步;该体系的特点是具有相当薄的,通常是而不总是混凝土的构件,这种构件既可提供结构强度,又可提供建筑物功能上的分隔;在高层建筑中,剪力墙体系趋向于具有相对大的高宽经,即与宽度相比,其高度偏大;由于基础体系缺少应力,任何一种结构构件抗倾覆弯矩的能力都受到体系的宽度和构件承受的重力荷载的限制;由于剪力墙宽度狭狭窄受限,所以需要以某种方式加以扩大,以便提从所需的抗倾覆能力;在窗户需要量小的建筑物外墙中明显地使用了这种确有所需要宽度的体系;钢结构剪力墙通常由混凝土覆盖层来加强以抵抗失稳,这在剪切荷载大的地方已得到应用;这种体系实际上比钢支撑经济,对于使剪切荷载由位于地面正上方区域内比较高的楼层向下移特别有效;这种体系还具有高延性之优点,这种特性在强震区特别重要;由于这些墙内必然出同一些大孔,使得剪力墙体系分析变得错综复杂;可以通过桁架模似法、有限元法,或者通过利用为考虑剪力墙的交互作用或扭转功能设计的专门计处机程序进行初步分析框架或支撑式筒体结构：框架或支撑式筒体最先应用于IBM公司在Pittsburgh的一幢办公楼,随后立即被应用于纽约双子座的110层世界贸易中心摩天大楼和其他的建筑中;这种系统有以下几个显着的特征：三维结构、支撑式结构、或由剪力墙形成的一个性质上差不多是圆柱体的闭合曲面,但又有任意的平面构成;由于这些抵抗侧向荷载的柱子差不多都被设置在整个系统的中心,所以整体的惯性得到提高,刚度也是很大的;在可能的情况下,通过三维概念的应用、二维的类比,我们可以进行筒体结构的分析;不管应用那种方法,都必须考虑剪力滞后的影响;这种最先在航天器结构中研究的剪力滞后出现后,对筒体结构的刚度是一个很大的限制;这种观念已经影响了筒体结构在60层以上建筑中的应用;设计者已经开发出了很多的技术,用以减小剪力滞后的影响,这其中最有名的是桁架的应用;框架或支撑式筒体在40层或稍高的建筑中找到了自己的用武之地;除了一些美观的考虑外,桁架几乎很少涉及与外墙联系的每个建筑功能,而悬索一般设置在机械的地板上,这就令机械体系设计师们很不赞成;但是,作为一个性价比较好的结构体系,桁架能充分发挥它的性能,所以它会得到设计师们持续的支持;由于其最佳位置正取决于所提供的桁架的数量,因此很多研究已经试图完善这些构件的位置;实验表明：由于这种结构体系的经济性并不十分受桁架位置的影响,所以这些桁架的位置主要取决于机械系统的完善,审美的要求,筒中筒结构：筒体结构系统能使外墙中的柱具有灵活性,用以抵抗颠覆和剪切力;“筒中筒”这个名字顾名思义就是在建筑物的核心承重部分又被包围了第二层的一系列柱子,它们被当作是框架和支撑筒来使用;配置第二层柱的目的是增强抗颠覆能力和增大侧移刚度;这些筒体不是同样的功能,也就是说,有些筒体是结构的,而有些筒体是用来支撑的;在考虑这种筒体时,清楚的认识和区别变形的剪切和弯曲分量是很重要的,这源于对梁的对比分析;在结构筒中,剪切构件的偏角和柱、纵梁例如：结构筒中的网等的弯曲有关,同时,弯曲构件的偏角取决于柱子的轴心压缩和延伸例如：结构筒的边缘等;在支撑筒中,剪切构件的偏角和对角线的轴心变形有关,而弯曲构件的偏角则与柱子的轴心压缩和延伸有关;根据梁的对比分析,如果平面保持原形例如：厚楼板,那么外层筒中柱的轴心压力就会与中心筒柱的轴心压力相差甚远,而且稳定的大于中心筒;但是在筒中筒结构的设计中,当发展到极限时,内部轴心压力会很高的,甚至远远大于外部的柱子;这种反常的现象是由于两种体系中的剪切构件的刚度不同;这很容易去理解,内筒可以看成是一个支撑或者说是剪切刚性的筒,而外筒可以看成是一个结构或者说是剪切弹性的筒;核心交互式结构：核心交互式结构属于两个筒与某些形式的三维空间框架相配合的筒中筒特殊情况;事实上,这种体系常用于那种外筒剪切刚度为零的结构;位于Pittsburgh的美国钢铁大楼证实了这种体系是能很好的工作的;在核心交互式结构中,内筒是一个支撑结构,外筒没有任何剪切刚度,而且两种结构体系能通过一个空间结构或“帽”式结构共同起作用;需要指出的是,如果把外部的柱子看成是一种从“帽”到基础的直线体系,这将是不合适的；根据支撑核心的弹性曲线,这些柱子只发挥了刚度的15%;同样需要指出的是,内柱中与侧向力有关的轴向力沿筒高度由拉力变为压力,同时变化点位于筒高度的约5/8处;当然,外柱也传递相同的轴向力,这种轴向力低于作用在整个柱子高度的侧向荷载,因为这个体系的剪切刚度接近于零;把内外筒相连接的空间结构、悬臂梁或桁架经常遵照一些规范来布置;美国电话电报总局就是一个布置交互式构件的生动例子;1、结构体系长米,宽米,高米;2、布置了两个筒,每个筒的尺寸是米×米,在长方向上有米的间隔;3、在短方向上内筒被支撑起来,但是在长方向上没有剪切刚度;4、环绕着建筑物布置了一个外筒;5、外筒是一个瞬时抵抗结构,但是在每个长方向的中心米都没有剪切刚度;6、在建筑的顶部布置了一个空间桁架构成的“帽式”结构;7、在建筑的底部布置了一个相似的空间桁架结构;8、由于外筒的剪切刚度在建筑的底部接近零,整个建筑基本上由两个钢板筒来支持;框格体系或束筒体系结构：位于美国芝加哥的西尔斯大厦是箱式结构的经典之作,它由九个相互独立的筒组成的一个集中筒;由于西尔斯大厦包括九个几乎垂直的筒,而且筒在平面上无须相似,基本的结构体系在不规则形状的建筑中得到特别的应用;一些单个的筒高于建筑一点或很多是很常见的;事实上,这种体系的重要特征就在于它既有坚固的一面,也有脆弱的一面;这种体系的脆弱,特别是在结构筒中,与柱子的压缩变形有很大的关系,柱子的压缩变形有下式计算：△=ΣfL/E对于那些层高为米左右和平均压力为138MPa的建筑,在荷载作用下每层柱子的压缩变形为1512/29000或毫米;在第50层柱子会压缩94毫米,小于它未受压的长度;这些柱子在50层的时候和100层的时候的变形是不一样的,位于这两种体系之间接近于边缘的那些柱需要使这种不均匀的变形得以调解;主要的结构工作都集中在布置中;在Melbourne的Rialto项目中,结构工程师发现至少有一幢建筑,很有必要垂直预压低高度的柱子,以便使柱不均匀的变形差得以调解,调解的方法近似于后拉伸法,即较短的柱转移重量到较高的邻柱上;。

帮我写一篇关于土木工程的英语作文英文回答：Civil engineering is a broad and challenging field that involves the design, construction, and maintenance ofpublic works, such as roads, bridges, dams, and buildings. Civil engineers play a vital role in shaping the built environment and ensuring its safety and sustainability.Civil engineering encompasses a wide range of disciplines, including structural engineering, geotechnical engineering, water resources engineering, transportation engineering, and environmental engineering. Structural engineers design and analyze the load-bearing components of buildings and bridges, ensuring their stability and strength. Geotechnical engineers study the behavior of soil and rock, and design foundations and earthworks that can withstand various loads and environmental conditions. Water resources engineers manage and distribute water resources, designing water treatment plants, dams, and irrigationsystems. Transportation engineers plan and design transportation systems, including roads, highways, airports, and railways. Environmental engineers focus on protecting the environment from the impacts of construction and development, designing systems for waste management, air pollution control, and water treatment.Civil engineering projects require a high level of technical expertise and collaboration. Civil engineers work closely with architects, planners, environmental scientists, and other professionals to ensure that projects meet functional, aesthetic, and environmental requirements. They use advanced software and modeling techniques to analyzeand design structures, and they must have a strong understanding of materials, construction methods, andproject management.Civil engineering is a stimulating and rewarding field that offers opportunities for professional growth and societal impact. Civil engineers have the opportunity to design and build structures that improve the quality oflife for people around the world, and they play a crucialrole in protecting the environment and promoting sustainable development.中文回答：土木工程是一个涉及公共工程（如道路、桥梁、水坝和建筑）的设计、建造和维护的广泛而具有挑战性的领域。