远场地震引起的单桩横向位移和内力

Lateral displacement and internal force of single pile induced by far-field earthquake

远场地震中 ,瑞利波能量是占优的。本文首先介绍了成层地基中瑞利波特征方程的解析解 ,然后采用文克勒地基梁模型 ,考虑单桩上部结构惯性力的影响 ,通过解析法建立了瑞利波作用下成层地基中单桩的横向动力响应计算公式。最后 ,将实际工程中抗震设计时的抗震设防烈度和设计特征周期结合起来 ,实例计算了不同的抗震设防烈度、场地特征周期、上部结构质量时单桩的横向动力响应 ,得到了一些有意义的结论 。

In the far field earthquake, the energy of the Rayleigh Waves is dominante. In this paper, firstly the analytical solution of dispersion curve of Rayleigh Wave in layered soils was presented. Then, the equation of lateral dynamic response of single pile with a mass on its top in layered soils induced by Rayleigh waves was deduced based on the Winkler beam model. Finally, several numerical examples are discussed. The effects of maxium acceleration,predominant period of ground surface motion and mass of superstructure on the lateral displacement and internal force of the pile were shown. The conclusions of this paper may be meaningful to the anti seismic design of piles.