强夯加固软土地基机理的有限元分析

Finite Element Analysis for Mechanism on Foundation Stabilization of Soft Clay by Dynamic Compaction Method

利用三维有限元法模拟强夯软土地基过程,对饱和土结构在受夯击时的变形及渗流情况进行分析,计算在夯击过程中地基内应力、位移、孔隙压力的变化,分析地基表面因夯击而引起的沉降位移和接触压力。结合现场实例分析对比,证明强夯加固软土地基完全可以用三维有限元程序进行精确模拟。试验数据及有限元模拟结果说明只要在能够确保人工排水体系的可靠运作,强夯垫层完全可以用粉细砂来取代,即在饱和软土地基强夯法加固过程中使用"无垫层"技术。与传统的强夯技术相比,强夯联合塑料排水板加固地基方法可以在不破坏土体原有结构的基础上实现加固饱和软土地基的功效。

Foundation stabilization of soft clay with dynamic compaction method is simulated by 3D finite element method (FEM). Deformation and seepage of saturated soft clay are analyzed in detail. Variety of stress, deformation and hydraulic pressure is calculated in foundation of soft clay. Deformation of ground and stress of interface are analyzed. Compared to the result of field test, it is proved that 3D FEM may analog the process of treating soft clay foundation with dynamic compaction method. It is known from test data and FEM simulation results, on the basis of good drainage, silt sand can be used as cushion of dynamic compaction method, known as none cushion technology. Compared to classical method, dynamic compaction associating with plastic drainage can treat soft clay foundation, and soil structure can be kept from damaging.