变刚度刚性桩复合地基抗震性能研究

Numerical research on aseismic behavior of variable stiffness rigid pile composite foundation

为了研究变刚度刚性桩复合地基的抗震性能,利用ANSYS分析软件建立了两种不同类型变刚度刚性桩复合地基及上部结构的有限元模型,采用时程分析法对变刚度刚性桩复合地基进行地震响应分析,得出了这两种变刚度刚性桩复合地基在地震作用下的桩体位移、内力最大值分布规律.结果表明,长桩的最大内力值远远大于短桩,大直径桩的最大内力值远远大于小直径桩,在抗震设防地区采用变刚度刚性桩复合地基需加强长桩和大直径桩的强度设计,并通过对比指出变桩长方案的刚性桩复合地基在同等经济条件下抗震性能优于变桩径方案.

In order to realizing the anti-seismic performance of a variable stiffness rigid pile composite - foun- dation, aseismic behavior of two kinds of the variable stiffness rigid pile composite foundation was analyzed by ANSYS. A kind of finite element analysis software, and the condition of displacement and internal force distri- butions were calculated out under the same seismic action. The result shows that the max internal force values of a long pile and of a large diameter pile is much more than that of a short pile and that of a small one. Thus- ly, the strength of a long pile and of a large diameter pile must be enhanced in aseismic design. By contrast, under the same economic conditions, the aseismic performance of a variable length pile is better than that of avariable diameter pile in a variable stiffness rigid pile composite foundation.