强夯荷载作用下地基竖向位移数值分析

为反映强夯荷载作用下地基竖向位移变化特点,基于功能原理推导出强夯荷载作用下等效接触拟静力峰值计算公式;借助ANSYS/LS-DYNA有限元软件建立强夯数值模型,将强夯荷载简化为三角形冲击荷载对强夯过程进行数值模拟,并以南通某强夯法处理冲填软土地基工程为实例对这一强夯后地基竖向位移计算方法进行了验证。实例计算结果表明:该方法计算得到的地基竖向体积变化占地基总体积变化的比例与实测相近;用体积变化比例代表能量分配系数计算得到的竖向位移值与实测值相近;该方法用于冲填软土地基是适用的。

Numerical analysis of vertical displacement of foundation under dynamic compaction load

In order to reflect the variation characteristics of the vertical displacement of foundation under dynamic compaction load, the formula for the peak value of the equivalent contact quasi-static force is derived based on the principle of work and power. The numerical model of dynamic compaction is established by the finite element software ANSYS/LS-DYNA, and the dynamic compaction load is simplified to triangular impact load. The settlement calculation method is verified by an actual project of which the soft soil foundation was filled by dynamic compaction in Nantong. The calculation results show that the ratio of the vertical volume variation to the total volume change of the foundation calculated by the proposed method is close to the measured value, and the settlement calculated by the proportion of volume variation representing the energy distribution coefficient agrees well with the measured value. Therefore, the calculation method of settlement after tamping is applicable to dredger fill soft soil foundation.