高层建筑结构形式The Structure Form of HighRise Buildings.docx

1、高层建筑结构形式The Structure Form of HighRise Buildings外文文献:The Structure Form of High-Rise BuildingsABSTRACT：High-rise building is to point to exceed a certain height and layers multistory buildings. In the United States, 24.6 m or 7 layer above as high-rise buildings; In Japan, 31m or 8 layer and above a

2、s high-rise buildings; In Britain, to have equal to or greater than 24.3 m architecture as high-rise buildings. Since 2005 provisions in China more than 10 layers of residential buildings and more than 24 meters tall other civil building for high-rise buildings. KEYWARD：High-Rise Buildings；Shear-Wal

3、l Systems；Rigid-Frame Systems1. High-rise building profilesAlthough 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 ver

4、tical 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 s

5、tory 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

6、 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.W

7、hen 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 rig

8、id 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 mome

9、nt 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

10、 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 ful

11、l 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 g

12、ravity 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 wi

13、ll 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 econo

14、my. (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 ve

15、rtical 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

16、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 th

17、e 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 forc

18、es 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,

19、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

20、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 verti

21、cal 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.2. Shear-Wall SystemsShe

22、ar wall structure is reinforced concrete wallboard to replace with beam-column frame structure of, can undertake all kinds of loads, and can cause the internal force of the structure effectively control the horizontal forces with reinforced concrete wallboard, the vertical and horizontal force to be

23、ar the structure called the shear wall structure. This structure was in high-rise building aplenty, so, homebuyers can need not be blinded by its terms. Shear wall structure refers to the vertical of reinforced concrete wallboard, horizontal direction is still reinforced concrete slab of carrying th

24、e wall, so big a system, that constitutes the shear wall structure. Why call shear wall structure, actually, the higher the wind load building to its push is bigger, so the wind direction of pushing that level, such as promoting the house, below was a binding, the above the wind blows should produce

25、 certain swing floating, swing floating restrictions on the very small, vertical wallboard to resist, the wind over, wants it has a force on top, make floor do not produce swing or shift float degrees small, in particular the bounds of structure, such as: the wind from one side, then there is a cons

26、iderable force board with it braved along the vertical wallboard, the height of the force, is equivalent to a pair of equivalent shearing, like a with scissors cut floor of force building and the farther down, accordingly, the shear strength of such wallboard that shear wall panels, also explains th

27、e wallboard vertical bearing of vertical force also not only should bear the horizontal wind loading, including the horizontal seismic forces to one of its push wind.When shear walls are compatible with other functional requirements, they can be economically utilized to resist lateral forces in high

28、-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. I

29、f 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) . Therefore, it is always necessary to provide shear walls in two perpen

30、dicular 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 sub

31、systems. 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 excel

32、lent Shear-Wall Systems 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

33、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 windows and for