强夯法填土地基处理有限元模拟研究

Finite element simulation of dynamic compaction method for foundation treatment

以某工程为例,采用大变形通用有限元程序LS-DYNA,对强夯法在该地基处理中的应用进行了数值模拟计算分析。模拟计算结果表明,随着夯击数的增加,土体等效应变逐渐从表层土体向地基深层和四周扩散,土体沉降逐渐增大;在经过4次夯击后,土体沉降可达到夯坑深度为2m的收锤标准;同时,土体的沉降量呈现出非线性增长趋势,沉降增幅逐渐降低;强夯应力波大致呈现圆弧形在土体中迅速向外扩散传播,应力强度衰减极快,与强夯加固的范围相关;最终对强夯设计方案进行一定修正。

Using an engineering case as an example, the application of dynamic compaction method in the treatment of a foundation is simulated and analyzed by the general large deformation finite element program LS-DYNA.The simulation results show that with the increase of compaction, the equivalent strain of soil gradually diffuses from the surface to the deep and surrounding foundation, and the foundation settlement gradually increases.After four-time compaction, the soil settlement can reach the terminative standard with a compaction pit depth of 2 m.At the same time, the soil settlement shows a nonlinear growth trend, the settlement increment decreases gradually.The stress wave of dynamic compaction spreads rapidly in the soil with a circular shape, and the stress intensity decays very quickly, which is related to the reinforcement range.Finally, the design of dynamic compaction is modified.