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.


前 沿
高層建筑的定義很難確定?？梢哉f2-3層的建筑物為底層建筑，而從3-4層地10層或20層的建筑物為中層建筑，高層建筑至少為10層或者更多。
盡管在原理上，高層建筑的豎向和水平構(gòu)件的設(shè)計同低層及多層建筑的設(shè)計沒什么區(qū)別，但使豎向構(gòu)件的設(shè)計成為高層設(shè)計有兩個控制性的因素：首先，高層建筑需要較大的柱體、墻體和井筒；更重要的是側(cè)向里所產(chǎn)生的傾覆力矩和剪力變形要大的多，必要謹(jǐn)慎設(shè)計來保證。
高層建筑的豎向構(gòu)件從上到下逐層對累積的重力和荷載進(jìn)行傳遞，這就要有較大尺寸的墻體或者柱體來進(jìn)行承載。同時，這些構(gòu)件還要將風(fēng)荷載及地震荷載等側(cè)向荷載傳給基礎(chǔ)。但是，側(cè)向荷載的分布不同于豎向荷載，它們是非線性的，并且沿著建筑物高度的增加而迅速地增加。例如，在其他條件都相同時，風(fēng)荷載在建筑物底部引起的傾覆力矩隨建筑物高度近似地成平方規(guī)律變化，而在頂部的側(cè)向位移與其高度的四次方成正比。地震荷載的效應(yīng)更為明顯。