A calculation method of soft soil pressure bearing mathematical model under repeated load

重复载荷下软土承压模型的计算方法研究

School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China

Received: 15 April 2022

Abstract

The soft soil pressure bearing mathematical model under repeated normal load is established and its program is implemented. The relationship of soft soil between pressure and settlement under repeated load is solved. Taking the settlement volume, contact area and loading times as independent variables and soil deformation force as dependent variables, the calculus equation of soil deformation force at the arbitrary position is deduced. The soil is discretized section by section in the settlement direction, and the bearing coefficient of the corresponding section is applied. During the unloading-loading period, the calculation formulas of the corresponding stable point and the stiffness of the soil rebounding line are given, and the load settlement program of soft soil is compiled. The soil stiffness value is substituted into the calculus equation, and the Adams software is redeveloped with C/C++language to obtain the load settlement curve. On the soft soil terrain, three kinds of flat plates with diameters of 6, 8, and 10 cm are used to carry out the pressure penetration test to obtain the corresponding pressure-settlement curve. The error between the simulation and experimental results of the mathematical model is no more than 10%.

摘要

对重复法向载荷下的软土承压模型进行数学建模及程序实现, 求解重复加载下软土的压力沉陷关系。以沉陷量、接触面积及加载次数为自变量, 土壤变形力为因变量, 推导任意位置土壤变形力的微积分方程。沿沉陷方向将土壤分段离散, 施加对应分段的分段承载系数, 并在卸载-加载期间, 给出对应的稳定点计算公式和土壤反弹线刚度, 编制松软土壤的载荷沉陷程序。将土壤刚度值代入微积分方程, 利用C/C++语言对Adams进行二次开发, 获得载荷沉陷曲线。在软土地形上, 利用直径为6, 8, 10 cm的3种平板, 实施压板贯入试验获得对应的压力-沉陷曲线, 模型的仿真与试验结果误差不超过10%。