建筑物桩基在地震荷载作用下的受力分析实际是一个动力计算问题。地震时,地震波通过土介质以弹性波形式向四周传播,土层振动引起桩基础的振动,桩基础振动能量又传给上部结构,上部结构振动反过来又以惯性力作用于桩基础和地基上,瞬时间桩承受了附加的垂直荷载、弯矩和水平剪力。在地震中上部结构-桩-地基土,三者相互作用比较复杂。近年来国外虽已开始研究试用动态法计算,但须要一个探索过程。目前,桩基的抗震设计大部分国家仍以静力法为主,即将上部结构(或包括地下部分)所受水平 The force analysis of a building pile foundation under a seismic load is actually a dynamic calculation problem. During an earthquake, seismic waves propagate through the soil medium in the form of elastic waves. The vibration of the soil layer causes vibration of the pile foundation. The vibration energy of the pile foundation is transmitted to the upper structure. The vibration of the upper structure in turn acts as inertia force on the pile foundation and foundation. The piles between the moments are subjected to additional vertical loads, bending moments and horizontal shear forces. In the earthquake, the interaction between the upper structure-pile-foundation soil is more complicated. Although foreign countries have begun to study the trial of dynamic method calculations in recent years, they need an exploration process. At present, the seismic design of pile foundations is still dominated by the static method in most countries, that is, the level of the superstructure (or including the underground part) will be affected.