沉桩挤土的数值模拟与土体物理参数的变化分析

由于沉桩造成的桩周土体的侧移和隆起对周围的建筑物和设施造成的事故时有发生，研究沉桩对周围土体的影响规律，对于控制这类工程事故的发生具有非常重要的意义。基于圆孔扩张法的基本思想，对以往分析中处理桩土接触问题的方法进行了简化，通过在接触边界上给土体施加位移边界条件来模拟桩对周围土体的作用，采用分段压入的方式对沉桩过程进行了有限元模拟，分析了沉桩后桩体周围土体的变形规律和力学行为，并且对沉桩完成后的土体的物理参数进行了量化分析，得到了压桩前后土体单元物理参数的量化关系式。

Numerical analysis of driving pile and study of physical parameters of soil

During the course of driving pile, the soil around pile will move literally and be hove. The constructions and establishments in site often destroyed. To decrease those accidents, it is significant to study the law of the effect on soil. Based on the theory of the expansion of hole and predigested the disposal of contact between pile and soil, looked on the process of driving pile as crushing soil step by step, simulated the effects on soil when driving pile through giving the displacement, this paper analyzed the process of driving pile, then the movement law and mechanical behavior of the soil was got. Finally, the physical parameters of the soil around pile were also studied and the equations of the connection between before and after driving pile obtained.