High-Rise Buildings
Introduction
It is difficult to define a high-rise building . One may say that a low-rise building ranges from 1 to 2 stories . A medium-rise building probably ranges between 3 or 4 stories up to 10 or 20 stories or more .
Although the basic principles of vertical and horizontal subsystem design remain the same for low- , medium- , or high-rise buildings , when a building gets high the vertical subsystems become a controlling problem for two reasons . Higher vertical loads will require larger columns , walls , and shafts . But , more significantly , the overturning moment and the shear deflections produced by lateral forces are much larger and must be carefully provided for .
The vertical subsystems in a high-rise building transmit accumulated gravity load from story to story , thus requiring larger column or wall sections to support such loading . In addition these same vertical subsystems must transmit lateral loads , such as wind or seismic loads , to the foundations. However , in contrast to vertical load , lateral load effects on buildings are not linear and increase rapidly with increase in height . For example under wind load , the overturning moment at the base of buildings varies approximately as the square of a buildings may vary as the fourth power of buildings height , other things being equal. Earthquake produces an even more pronounced effect.
When the structure for a low-or medium-rise building is designed for dead and live load , it is almost an inherent property that the columns , walls , and stair or elevator shafts can carry most of the horizontal forces . The problem is primarily one of shear resistance . Moderate addition bracing for rigid frames in“short”buildings can easily be provided by filling certain panels ( or even all panels ) without increasing the sizes of the columns and girders otherwise required for vertical loads.
Unfortunately , this is not is for high-rise buildings because the problem is primarily resistance to moment and deflection rather than shear alone . Special structural arrangements will often have to be made and additional structural material is always required for the columns ,
girders , walls , and slabs in order to made a high-rise buildings sufficiently resistant to much higher lateral deformations .
As previously mentioned , the quantity of structural material required per square foot of floor of a high-rise buildings is in excess of that required for low-rise buildings . The vertical components carrying the gravity load , such as walls , columns , and shafts , will need to be strengthened over the full height of the buildings . But quantity of material required for resisting lateral forces is even more significant .
With reinforced concrete , the quantity of material also increases as the number of stories increases . But here it should be noted that the increase in the weight of material added for gravity load is much more sizable than steel , whereas for wind load the increase for lateral force resistance is not that much more since the weight of a concrete buildings helps to resist overturn . On the other hand , the problem of design for earthquake forces . Additional mass in the upper floors will give rise to a greater overall lateral force under the of seismic effects .
In the case of either concrete or steel design , there are certain basic principles for providing additional resistance to lateral to lateral forces and deflections in high-rise buildings without too much sacrifire in economy .
1.Increase the effective width of the moment-resisting subsystems . This is very useful
because increasing the width will cut down the overturn force directly and will reduce
deflection by the third power of the width increase , other things remaining cinstant .
However , this does require that vertical components of the widened subsystem be
suitably connected to actually gain this benefit.
2.Design subsystems such that the components are made to interact in the most efficient
manner . For example , use truss systems with chords and diagonals efficiently
stressed , place reinforcing for walls at critical locations , and optimize stiffness ratios
for rigid frames .
3.Increase the material in the most effective resisting components . For example ,
materials added in the lower floors to the flanges of columns and connecting girders
will directly decrease the overall deflection and increase the moment resistance
without contributing mass in the upper floors where the earthquake problem is
aggravated .
4.Arrange to have the greater part of vertical loads be carried directly on the primary
moment-resisting components . This will help stabilize the buildings against tensile
overturning forces by precompressing the major overturn-resisting components .
5.The local shear in each story can be best resisted by strategic placement if solid walls
or the use of diagonal members in a vertical subsystem . Resisting these shears solely
by vertical members in bending is usually less economical , since achieving sufficient
bending resistance in the columns and connecting girders will require more material
and construction energy than using walls or diagonal members .
6.Sufficient horizontal diaphragm action should be provided floor . This will help to
bring the various resisting elements to work together instead of separately .
7.Create mega-frames by joining large vertical and horizontal components such as two
or more elevator shafts at multistory intervals with a heavy floor subsystems , or by
use of very deep girder trusses .
Remember that all high-rise buildings are essentially vertical cantilevers which are supported at the ground . When the above principles are judiciously applied , structurally desirable schemes can be obtained by walls , cores , rigid frames, tubular construction , and other vertical subsystems to achieve horizontal strength and rigidity . Some of these applications will now be described in subsequent sections in the following .
The vertical subsystems in a high-rise building transmit accumulated gravity load from story to story , thus requiring larger column or wall sections to support such loading . In addition these same vertical subsystems must transmit lateral loads , such as wind or seismic loads , to the foundations. However , in contrast to vertical load , lateral load effects on buildings are not linear and increase rapidly with increase in height . For example under wind load , the overturning moment at the base of buildings varies approximately as the square of a buildings may vary as the fourth power of buildings height , other things being equal. Earthquake produces an even more pronounced effect.
When the structure for a low-or medium-rise building is designed for dead and live load , it is almost an inherent property that the columns , walls , and stair or elevator shafts can carry most of the horizontal forces . The problem is primarily one of shear resistance . Moderate addition bracing for rigid frames in“short”buildings can easily be provided by filling certain panels ( or even all panels ) without increasing the sizes of the columns and girders otherwise required for vertical loads.
With reinforced concrete , the quantity of material also increases as the number of stories increases . But here it should be noted that the increase in the weight of material added for gravity load is much more sizable than steel , whereas for wind load the increase for lateral force resistance is not that much more since the weight of a concrete buildings helps to resist overturn . On the other hand , the problem of design for earthquake forces . Additional mass in the upper floors will give rise to a greater overall lateral force under the of seismic effects .
In the case of either concrete or steel design , there are certain basic principles for providing additional resistance to lateral to lateral forces and deflections in high-rise buildings without too much sacrifire in economy . Increase the effective width of the moment-resisting subsystems . This is very useful because increasing the width will cut down the overturn force directly and will reduce deflection by the third power of the width increase , other things remaining cinstant . However , this does require that vertical components of the widened subsystem be suitably connected to actually gain this benefit.Design subsystems such that the components are made to interact in the most efficient manner .
Remember that all high-rise buildings are essentially vertical cantilevers which are supported at the ground . When the above principles are judiciously applied , structurally desirable schemes can be obtained by walls , cores , rigid frames, tubular construction , and other vertical subsystems to achieve horizontal strength and rigidity . Some of these applications will now be described in subsequent sections in the following .
Shear-Wall Systems
When shear walls are compatible with other functional requirements , they can be economically utilized to resist lateral forces in high-rise buildings . For example , apartment buildings naturally require many separation walls . When some of these are designed to be solid , they can act as shear walls to resist lateral forces and to carry the vertical load as well . For buildings up to some 20storise , the use of shear walls is common . If given sufficient length ,such walls can economically resist lateral forces up to 30 to 40 stories or more .
However , shear walls can resist lateral load only the plane of the walls ( i.e.not in a diretion perpendicular to them ) . There fore ,it is always necessary to provide shear walls in two perpendicular directions can be at least in sufficient orientation so that lateral force in any direction can be resisted . In addition , that wall layout should reflect consideration of any torsional effect .
In design progress , two or more shear walls can be connected to from L-shaped or channel-shaped subsystems . Indeed , internal shear walls can be connected to from a rectangular shaft that will resist lateral forces very efficiently . If all external shear walls are continuously connected , then the whole buildings acts as tube , and connected , then the whole buildings acts as a tube , and is excellent Shear-Wall Seystems resisting lateral loads and torsion .
Whereas concrete shear walls are generally of solid type with openings when necessary , steel shear walls are usually made of trusses . These trusses can have single diagonals , “X”diagonals , or“K”arrangements . A trussed wall will have its members act essentially in direct tension or compression under the action of view , and they offer some opportunity and deflection-limitation point of view , and they offer some opportunity for penetration between members . Of course , the inclined members of trusses must be suitable placed so as not to interfere with requirements for wiondows and for circulation service penetrations though these walls .
In many high-rise buildings , a combination of walls and shafts can offer excellent resistance to lateral forces when they are suitably located ant connected to one another . It is also desirable that the stiffness offered these subsystems be more-or-less symmertrical in all directions .
Rigid-Frame Systems
In the design of architectural buildings , rigid-frame systems for resisting vertical and lateral loads have long been accepted as an important and standard means for designing building . They are employed for low-and medium means for designing buildings . They are employed for low- and medium up to high-rise building perhaps 70 or 100 stories high . When compared to shear-wall systems , these rigid frames both within and at the outside of a buildings . They also make use of the stiffness in beams and columns that are required for the buildings in any case , but the columns are made stronger when rigidly connected to resist the lateral as well as vertical forces though frame bending .
Frequently , rigid frames will not be as stiff as shear-wall construction , and therefore may produce excessive deflections for the more slender high-rise buildings designs . But because of this flexibility , they are often considered as being more ductile and thus less susceptible to catastrophic earthquake failure when compared with ( some ) shear-wall designs . For example , if over stressing occurs at certain portions of a steel rigid frame ( i.e.,near the joint ) , ductility will allow the structure as a whole to deflect a little more , but it will by no means collapse even under a much larger force than expected on the structure . For this reason , rigid-frame construction is considered by some to be a “best”seismic-resisting type for high-rise steel buildings . On the other hand ,it is also unlikely that a well-designed share-wall system would collapse.
In the case of concrete rigid frames ,there is a divergence of opinion . It true that if a concrete rigid frame is designed in the conventional manner , without special care to produce higher ductility , it will not be able to withstand a catastrophic earthquake that can produce forces several times lerger than the code design earthquake forces . therefore , some believe that it may not have additional capacity possessed by steel rigid frames . But modern research and experience has indicated that concrete frames can be designed to be ductile , when sufficient stirrups and joinery reinforcement are designed in to the frame . Modern buildings codes have specifications for the so-called ductile concrete frames . However , at present , these codes often require excessive reinforcement at certain points in the frame so as to cause congestion and result
in construction difficulties 。Even so , concrete frame design can be both effective and economical 。
Of course , it is also possible to combine rigid-frame construction with shear-wall systems in one buildings ，For example , the buildings geometry may be such that rigid frames can be used in one direction while shear walls may be used in the other direction。
Structural Systems to resist lateral loads
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.Tube-in-tube structures.
6.Core-interactive structures.
7.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.
Perhaps 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.
The 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 in conjunction 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.
The 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 sys tem 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 Tubes
The 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.
The tubular framing system mobilizes every column in the exterior wall in 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 (i.e, the webs of the framed tube) while the flexural component is associated with the axial shortening and lengthening of columns (i.e, 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 (i.e, 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 even higher, 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 (i.e, shear-stiff) tube while the outer tube is conceived as a framed (i.e, shear-flexible) tube.
高层建筑
前沿
高层建筑的定义很难确定。可以说2-3层的建筑物为底层建筑，而从3-4层地10层或20层的建筑物为中层建筑，高层建筑至少为10层或者更多。
尽管在原理上，高层建筑的竖向和水平构件的设计同低层及多层建筑的设计没什么区别，但使竖向构件的设计成为高层设计有两个控制性的因素：首先，高层建筑需要较大的柱体、墙体和井筒；更重要的是侧向里所产生的倾覆力矩和剪力变形要大的多，必要谨慎设计来保证。
高层建筑的竖向构件从上到下逐层对累积的重力和荷载进行传递，这就要有较大尺寸的墙体或者柱体来进行承载。同时，这些构件还要将风荷载及地震荷载等侧向荷载传给基础。但是，侧向荷载的分布不同于竖向荷载，它们是非线性的，并且沿着建筑物高度的增加而迅速地增加。例如，在其他条件都相同时，风荷载在建筑物底部引起的倾覆力矩随建筑物高度近似地成平方规律变化，而在顶部的侧向位移与其高度的四次方成正比。地震荷载的效应更为明显。
对于低层和多层建筑物设计只需考虑恒荷载和部分动荷载时，建筑物的柱、墙、楼梯或电梯等就自然能承受大部分水平力。所考虑的问题主要是抗剪问题。对于现代的钢架系统支撑设计，如无特殊承载需要，无需加大柱和梁的尺寸，而通过增加板就可以实现。
不幸的是，对于高层建筑首先要解决的不仅仅是抗剪问题，还有抵抗力矩和抵抗变形问题。高层建筑中的柱、梁、墙及板等经常需要采用特殊的结构布置和特殊的材料，以抵抗相当高的侧向荷载以及变形。
如前所述，在高层建筑中每平方英尺建筑面积结构材料的用量要高于低层建筑。支撑重力荷载的竖向构件，如墙、柱及井筒，在沿建筑物整个高度方向上都应予以加强。用于抵抗侧向荷载的材料要求更多。
对于钢筋混凝土建筑，虽着建筑物层数的增加，对材料的要求也随着增加。应当注意的是，因混凝土材料的质量增加而带来的建筑物自重增加，要比钢结构增加得多，而为抵抗风荷载的能力而增加的材料用量却不是呢么多，因为混凝土自身的重量可以抵抗倾覆力矩。不过不利的一面是混凝土建筑自重的增加，将会加大抗震设计的难度。在地震荷载作用下，顶部质量的增加将会使侧向荷载剧增。
无论对于混凝土结构设计，还是对于钢结构设计，下面这些基本的原则都有助于在不需要增加太多成本的前提下增强建筑物抵抗侧向荷载的能力。
1.增加抗弯构件的有效宽度。由于当其他条件不变时能够直接减小扭矩，
并以宽度增量的三次幂形式减小变形，因此这一措施非常有效。但是必须保证
加宽后的竖向承重构件非常有效地连接。
2.在设计构件时，尽可能有效地使其加强相互作用力。例如，可以采用
具有有效应力状态的弦杆和桁架体系；也可在墙的关键位置加置钢筋；以及最
优化钢架的刚度比等措施。
3.增加最有效的抗弯构件的截面。例如，增加较低层柱以及连接大梁的
翼缘截面，将可直接减少侧向位移和增加抗弯能力，而不会加大上层楼面的质
量，否则，地震问题将更加严重。
4.通过设计使大部分竖向荷载，直接作用于主要的抗弯构件。这样通过
预压主要的抗倾覆构件，可以使建筑物在倾覆拉力的作用下保持稳定。
5.通过合理地放置实心墙体及在竖向构件中使用斜撑构件，可以有效地
抵抗每层的局部剪力。但仅仅通过竖向构件进行抗剪是不经济的，因为使柱及
梁有足够的抗弯能力，比用墙或斜撑需要更多材料和施工工作量。
6.每层应加设充足的水平隔板。这样就会使各种抗力构件更好地在一起
工作，而不是单独工作。
7.在中间转换层通过大型竖向和水平构件及重楼板形成大框架，或者采
用深梁体系。
应当注意的是，所有高层建筑的本质都是地面支撑的悬臂结构。如何合理地运用上面所提到的原则，就可以利用合理地布置墙体、核心筒、框架、筒式结构和其他竖向结构分体系，使建筑物取得足够的水平承载力和刚度。本文后面将对这些原理的应用做介绍。
高层建筑的竖向构件从上到下逐层对累积的重力和荷载进行传递，这就要有较大尺寸的墙体或者柱体来进行承载。同时，这些构件还要将风荷载及地震
荷载等侧向荷载传给基础。但是，侧向荷载的分布不同于竖向荷载，它们是非
线性的，并且沿着建筑物高度的增加而迅速地增加。例如，在其他条件都相同
时，风荷载在建筑物底部引起的倾覆力矩随建筑物高度近似地成平方规律变化，
而在顶部的侧向位移与其高度的四次方成正比。地震荷载的效应更为明显。
对于低层和多层建筑物设计只需考虑恒荷载和部分动荷载时，建筑物的
柱、墙、楼梯或电梯等就自然能承受大部分水平力。所考虑的问题主要是抗剪问题。对于现代的钢架系统支撑设计，如无特殊承载需要，无需加大柱和梁的尺寸，而通过增加板就可以实现。
对于钢筋混凝土建筑，虽着建筑物层数的增加，对材料的要求也随着增加。应当注意的是，因混凝土材料的质量增加而带来的建筑物自重增加，要比钢结构增加得多，而为抵抗风荷载的能力而增加的材料用量却不是呢么多，因为混凝土自身的重量可以抵抗倾覆力矩。不过不利的一面是混凝土建筑自重的增加，将会加大抗震设计的难度。在地震荷载作用下，顶部质量的增加将会使侧向荷载剧增。
无论对于混凝土结构设计，还是对于钢结构设计，下面这些基本的原则都有助于在不需要增加太多成本的前提下增强建筑物抵抗侧向荷载的能力。增加抗弯构件的有效宽度。由于当其他条件不变时能够直接减小扭矩，并以宽度增量的三次幂形式减小变形，因此这一措施非常有效。但是必须保证加宽后的竖向承重构件非常有效地连接。在设计构件时，尽可能有效地使其加强相互作用力。
应当注意的是，所有高层建筑的本质都是地面支撑的悬臂结构。如何合理地运用上面所提到的原则，就可以利用合理地布置墙体、核心筒、框架、筒式结构和其他竖向结构分体系，使建筑物取得足够的水平承载力和刚度。本文后面将对这些原理的应用做介绍。
剪力墙结构
在能够满足其他功能需求时，高层建筑中采用剪力墙可以经济地进行高层建筑的抗侧向荷载设计。例如，住宅楼需要很多隔墙，如果这些隔墙都设计为实例的，那么他们可以起到剪力墙的作用，既能抵抗侧向荷载，又能承受竖向荷载。对于20层以上的建筑物，剪力墙极为常见。如果给与足够的宽度，剪力墙能够有效地抵抗30-40层甚至更多的侧向荷载。
但是，剪力墙只能抵抗平行于墙平面的荷载（也就是说不能抵抗垂直于墙的荷载）。因此有必要经常在两个相互垂直的方向设置剪力墙，或者在尽可能多
的方向布置，以用来抵抗各个方向的侧向荷载。并且，墙体设计还应考虑扭转的问题。
在设计过程中，两片或者更多的剪力墙会布置成L型或者槽形。实际上，四片内剪力墙可以被联结成矩形，以更有效地抵抗侧向荷载。如果所有外部剪力墙都连接起来，整个建筑物就像是一个筒体，将会具有很强的抵抗水平荷载和抵抗扭矩的能力。
通常混凝土就剪力墙都是实体的，并在有要求时开洞，而钢筋剪力墙常常是做成桁架式。这些桁架上可能布置成蛋单斜撑、X斜撑及K斜撑。在侧向力作用下这些桁架的组合构件受到或拉或压力。从强度和变形控制角度来说，桁架有着很好的功效，并且管道可以在构件之间穿过。当然，钢桁架墙的斜向构件在墙体上要正确放置，以免妨碍开窗、循环以及管道穿墙。
对于很多高层建筑，如果墙体和筒架进行合理地安排与连接，会起到很好的抵抗侧向荷载的作用。还要求由这些结构分体系提供的刚度在各个方向上应大体对称。
框架结构
在建筑物结构设计中，用于抵抗竖向和水平荷载的框架结构，常作为一个重要且标准的型式而被采用。它适用于低层、多层建筑物，亦可用于70-100层高的高层建筑物。同剪力墙结构相比，这种结构更适合在建筑物的内部或者外围的墙体上开设矩形孔洞。同时它还能充分利用建筑物内在任何情况下都要采用的梁和柱的刚度，但当柱子与梁刚性连接时，通过框架受弯来抵抗水平和竖向荷载会使这些柱子的承载能力变得更大。
大多情况下，框架的刚度不如剪力墙，因此对于细长的建筑物将会出现过度变形。但正是因为其柔性，使得其与剪力墙结构相比具有更大的延性，因而地震荷载下不易发生事故。例如，如果框架局部出现超应力时，那么其延性就会允许整个结构出现倒塌事故。因此，框架结构常被视为最好的高层抗震结构。另一方面，设计得好的剪力墙结构也不可能倒塌。
对于混凝土框架结构，还存在较大的分歧。的确。如果在混凝土框架设计时不进行特殊的延性设计，那么他将很难承受比设计标准值大很多倍的地震荷
载的冲击。因此，很多人认为它不具备钢框架所具备的超载能力。不过最新的研究i和实验表明，当混凝土中放入充分的钢箍和节点钢筋时，混凝土框架框架也能表现出很好的延性。新建筑规范对所谓延性混凝土框架有专门的规定。然而，这些规范往往要求在框架的某处增设过多的钢筋，这就增加了施工的难度。尽管这样，混凝土框架设计还是具备既经济又实用的特性。
当然，还可以在建筑结构设计中，将框架结构和剪力墙结构结合起来使用。例如，在房屋建筑上使用框架，而在另一方向上可以使用剪力墙。
抗侧向荷载的结构体系
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。
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。
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著的特征：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。
出处：土木工程英语，科学出版社，张倩主编
PA VEMENT PROBLEMS CAUSED BY COLLAPSIBLE SUBGRADES By Sandra L. Houston,1 Associate Member, ASCE (Reviewed by the Highway Division) ABSTRACT: Problem subgrade materials consisting of collapsible soils are com- mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used. INTRODUCTION When a soil is given free access to water, it may decrease in volume, increase in volume, or do nothing. A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollars in roadway repairs. The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing with these problem subgrade materials. Each project will have different design considerations, economic con- straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/ or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem. The emphasis here will be placed on presenting economical and simple methods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287. Note. Discussion open until April 1, 1989. To extend the closing date one month,
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
The smart grid Smart grid is the grid intelligent (electric power), also known as the "grid" 2.0, it is based on the integration, high-speed bidirectional communication network, on the basis of through the use of advanced sensor and measuring technology, advanced equipme nt technology, the advanced control method, and the application of advanced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly and use the security target, its main features include self-healing, incentives and include user, against attacks, provide meet user requirements of power quality in the 21st century, allow all sorts of different power generation in the form of access, start the electric power market and asset optimizatio n run efficiently. The U.S. department of energy (doe) "the Grid of 2030" : a fully automated power transmission network, able to monitor and control each user and power Grid nodes, guarantee from power plants to end users among all the nodes in the whole process of transmission and distribution of information and energy bi-directional flow. China iot alliance between colleges: smart grid is made up of many parts, can be divided into:intelligent substation, intelligent power distribution network, intelli gent watt-hourmeter,intelligent interactive terminals, intelligent scheduling, smart appliances, intelligent building electricity, smart city power grid, smart power generation system, the new type of energy storage system.Now a part of it to do a simple i ntroduction. European technology BBS: an integration of all users connected to the power grid all the behavior of the power transmission network, to provide sustained and effective economic and security of power. Chinese academy of sciences, institute of electrical: smart grid is including all kinds of power generation equipment, power transmission and distribution network, power equipment and storage equipment, on the basis of the physical power grid will be modern advanced sensor measurement technology, network technology, communication
转型衰退时期的土木工程研究 Sergios Lambropoulosa[1], John-Paris Pantouvakisb, Marina Marinellic 摘要 最近的全球经济和金融危机导致许多国家的经济陷入衰退，特别是在欧盟的周边。这些国家目前面临的民用建筑基础设施的公共投资和私人投资显著收缩，导致在民事特别是在民用建筑方向的失业。因此，在所有国家在经济衰退的专业发展对于土木工程应届毕业生来说是努力和资历的不相称的研究，因为他们很少有机会在实践中积累经验和知识，这些逐渐成为过时的经验和知识。在这种情况下，对于技术性大学在国家经济衰退的计划和实施的土木工程研究大纲的一个实质性的改革势在必行。目的是使毕业生拓宽他们的专业活动的范围，提高他们的就业能力。 在本文中，提出了土木工程研究课程的不断扩大，特别是在发展的光毕业生的潜在的项目，计划和投资组合管理。在这个方向上，一个全面的文献回顾，包括ASCE体为第二十一世纪，IPMA的能力的基础知识，建议在其他：显著增加所提供的模块和项目管理在战略管理中添加新的模块，领导行为，配送管理，组织和环境等；提供足够的专业训练五年的大学的研究；并由专业机构促进应届大学生认证。建议通过改革教学大纲为土木工程研究目前由国家技术提供了例证雅典大学。 1引言 土木工程研究（CES）蓬勃发展，是在第二次世界大战后。土木工程师的出现最初是由重建被摧毁的巨大需求所致，目的是更多和更好的社会追求。但是很快，这种演变一个长期的趋势，因为政府为了努力实现经济发展，采取了全世界的凯恩斯主义的理论，即公共基础设施投资作为动力。首先积极的结果导致公民为了更好的生活条件（住房，旅游等）和增加私人投资基础设施而创造机会。这些现象再国家的发展中尤为为明显。虽然前景并不明朗（例如，世界石油危机在70年代），在80年代领先的国家采用新自由主义经济的方法（如里根经济政策），这是最近的金融危机及金融危机造成的后果（即收缩的基础设施投资，在技术部门的高失业率），消除发展前途无限的误区。 技术教育的大学所认可的大量研究土木工程部。旧学校拓展专业并且新的学校建成，并招收许多学生。由于高的职业声望，薪酬，吸引高质量的学校的学生。在工程量的增加和科学技术的发展，导致到极强的专业性，无论是在研究还是工作当中。结构工程师，液压工程师，交通工程师等，都属于土木工程。试图在不同的国家采用专业性的权利，不同的解决方案，，从一个统一的大学学历和广泛的专业化的一般职业许可证。这个问题在许多其他行业成为关键。国际专业协会的专家和机构所确定的国家性检查机构，经过考试后，他们证明不仅是行业的新来者，而且专家通过时间来确定进展情况。尽管在很多情况下，这些证书虽然没有国家接受，他们赞赏和公认的世界。 在试图改革大学研究（不仅在土木工程）更接近市场需求的过程中，欧盟确定了1999博洛尼亚宣言，它引入了一个二能级系统。第一级度（例如，一个三年的学士）是进入
姓名： 学号： 10447425 X X 大学 毕业设计（论文）外文翻译 （2014届） 外文题目Developments in excavation bracing systems 译文题目开挖工程支撑体系的发展 外文出处Tunnelling and Underground Space Technology 31 (2012) 107–116 学生XXX 学院XXXX 专业班级XXXXX 校内指导教师XXX 专业技术职务XXXXX 校外指导老师专业技术职务 二○一三年十二月
开挖工程支撑体系的发展 1.引言 几乎所有土木工程建设项目（如建筑物，道路，隧道，桥梁，污水处理厂，管道，下水道）都涉及泥土挖掘的一些工程量。往往由于由相邻的结构，特性线，或使用权空间的限制，必须要一个土地固定系统，以允许土壤被挖掘到所需的深度。历史上，许多挖掘支撑系统已经开发出来。其中，现在比较常见的几种方法是：板桩，钻孔桩墙，泥浆墙。 土地固定系统的选择是由技术性能要求和施工可行性（例如手段，方法）决定的，包括执行的可靠性，而成本考虑了这些之后，其他问题也得到解决。通常环境后果（用于处理废泥浆和钻井液如监管要求）也非常被关注（邱阳、1998）。 土地固定系统通常是建设项目的较大的一个组成部分。如果不能按时完成项目，将极大地影响总成本。通常首先建造支撑，在许多情况下，临时支撑系统是用于支持在挖掘以允许进行不断施工，直到永久系统被构造。临时系统可以被去除或留在原处。 打桩时，因撞击或振动它们可能会被赶入到位。在一般情况下，振动是最昂贵的方法，但只适合于松散颗粒材料，土壤中具有较高电阻（例如，通过鹅卵石）的不能使用。采用打入桩系统通常是中间的成本和适合于软沉积物（包括粘性和非粘性），只要该矿床是免费的鹅卵石或更大的岩石。 通常，垂直元素（例如桩）的前安装挖掘工程和水平元件（如内部支撑或绑回）被安装为挖掘工程的进行下去，从而限制了跨距长度，以便减少在垂直开发弯矩元素。在填充情况下，桩可先设置，从在斜坡的底部其嵌入悬挑起来，安装作为填充进步水平元素（如搭背或土钉）。如果滞后是用来保持垂直元素之间的土壤中，它被安装为挖掘工程的进行下去，或之前以填补位置。 吉尔- 马丁等人（2010）提供了一个数值计算程序，以获取圆形桩承受轴向载荷和统一标志（如悬臂桩）的单轴弯矩的最佳纵筋。他们开发的两种优化流程：用一个或两个直径为纵向钢筋。优化增强模式允许大量减少的设计要求钢筋的用量，这些减少纵向钢筋可达到50％相对传统的，均匀分布的加固方案。 加固桩集中纵向钢筋最佳的位置在受拉区。除了节约钢筋，所述非对称加强钢筋图案提高抗弯刚度，通过增加转动惯量的转化部分的时刻。这种增加的刚性可能会在一段时间内增加的变形与蠕变相关的费用。评估相对于传统的非对称加强桩的优点，对称，钢筋桩被服务的条件下全面测试来完成的，这种试验是为了验证结构的可行性和取得的变形的原位测量。 基于现场试验中，用于优化的加强图案的优点浇铸钻出孔（CIDH）在巴塞罗那的
New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.
Computer Program 1 Introduction Computer Program, set of instructions that directs a computer to perform someprocessing function or combination of functions. For the instructions to be carried out, a computer must execute a program, that is, the computer reads the program, and then follow the steps encoded in the program in a precise order until completion. A program can be executed many different times, with each execution yielding a potentially different result depending upon the options and data that the user gives the computer. Programs fall into two major classes: application programs and operating systems. An application program is one that carries out somefunction directly for a user, such as word processing or game-playing. An operating system is a program that manages the computer and the various resources and devices connected to it, such as RAM,hard drives, monitors, keyboards, printers, and modems,so that they maybe used by other programs. Examples of operating systems are DOS, Windows 95, OS\2, and UNIX. 2 Program Development Software designers create new programs by using special applications programs, often called utility programs or development programs. A programmer uses another type of program called a text editor to write the new program in a special notation called a programming language. With the text editor, the programmer creates a text file, which is an ordered list of instructions, also called the program source file. The individual instructions that make up the program source file are called source code. At this point, a special applications program translates the source code into machine language, or object code— a format that the operating system
项目成本控制 一、引言 项目是企业形象的窗口和效益的源泉。随着市场竞争日趋激烈，工程质量、文明施工要求不断提高，材料价格波动起伏，以及其他种种不确定因素的影响，使得项目运作处于较为严峻的环境之中。由此可见项目的成本控制是贯穿在工程建设自招投标阶段直到竣工验收的全过程，它是企业全面成本管理的重要环节，必须在组织和控制措施上给于高度的重视，以期达到提高企业经济效益的目的。 二、概述 工程施工项目成本控制，指在项目成本在成本发生和形成过程中，对生产经营所消耗的人力资源、物资资源和费用开支，进行指导、监督、调节和限制，及时预防、发现和纠正偏差从而把各项费用控制在计划成本的预定目标之内，以达到保证企业生产经营效益的目的。 三、施工企业成本控制原则 施工企业的成本控制是以施工项目成本控制为中心，施工项目成本控制原则是企业成本管理的基础和核心，施工企业项目经理部在对项目施工过程进行成本控制时，必须遵循以下基本原则。 3.1 成本最低化原则。施工项目成本控制的根本目的，在于通过成本管理的各种手段，促进不断降低施工项目成本，以达到可能实现最低的目标成本的要求。在实行成本最低化原则时，应注意降低成本的可能性和合理的成本最低化。一方面挖掘各种降低成本的能力，使可能性变为现实；另一方面要从实际出发，制定通过主观努力可能达到合理的最低成本水平。 3.2 全面成本控制原则。全面成本管理是全企业、全员和全过程的管理，亦称“三全”管理。项目成本的全员控制有一个系统的实质性内容，包括各部门、各单位的责任网络和班组经济核算等等，应防止成本控制人人有责，人人不管。项目成本的全过程控制要求成本控制工作要随着项目施工进展的各个阶段连续 进行，既不能疏漏，又不能时紧时松，应使施工项目成本自始至终置于有效的控制之下。 3.3 动态控制原则。施工项目是一次性的，成本控制应强调项目的中间控制，即动态控制。因为施工准备阶段的成本控制只是根据施工组织设计的具体内容确
（ 二 〇 一 二 年 六 月 外文文献及翻译 题 目： About Buiding on the Structure Design 学生姓名： 学 院：土木工程学院 系 别：建筑工程系 专 业：土木工程(建筑工程方向) 班 级：土木08-4班 指导教师：
英文原文： Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing Foreword Concrete'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
英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,
专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文 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。
7 Rigid-Frame Structures A rigid-frame high-rise structure typically comprises parallel or orthogonally arranged bents consisting of columns and girders with moment resistant joints. Resistance to horizontal loading is provided by the bending resistance of the columns, girders, and joints. The continuity of the frame also contributes to resisting gravity loading, by reducing the moments in the girders. The advantages of a rigid frame are the simplicity and convenience of its rectangular form.Its unobstructed arrangement, clear of bracing members and structural walls, allows freedom internally for the layout and externally for the fenestration. Rig id frames are considered economical for buildings of up to' about 25 stories, above which their drift resistance is costly to control. If, however, a rigid frame is combined with shear walls or cores, the resulting structure is very much stiffer so that its height potential may extend up to 50 stories or more. A flat plate structure is very similar to a rigid frame, but with slabs replacing the girders As with a rigid frame, horizontal and vertical loadings are resisted in a flat plate structure by the flexural continuity between the vertical and horizontal components. As highly redundant structures, rigid frames are designed initially on the basis of approximate analyses, after which more rigorous analyses and checks can be made. The procedure may typically inc lude the following stages: 1. Estimation of gravity load forces in girders and columns by approximate method. 2. Preliminary estimate of member sizes based on gravity load forces with arbitrary increase in sizes to allow for horizontal loading. 3. Approximate allocation of horizontal loading to bents and preliminary analysis of member forces in bents. 4. Check on drift and adjustment of member sizes if necessary. 5. Check on strength of members for worst combination of gravity and horizontal loading, and adjustment of member sizes if necessary. 6. Computer analysis of total structure for more accurate check on member strengths and drift, with further adjustment of sizes where required. This stage may include the second-order P-Delta effects of gravity loading on the member forces and drift.. 7. Detailed design of members and connections.