刚性挡土墙平动模式下中间被动土压力的计算

Calculation of inter-mediate passive earth pressure against rigid retaining wall with translation mode

为了准确地设计挡土墙,研究非极限位移时的土压力计算.将非极限状态下的被动土压力定义为中间被动土压力,分析土体的破坏机理,建立内外摩擦角与位移之间的关系公式.改进库仑土压力理论,根据静力平衡条件,推导出在刚性挡土墙平动模式下中间被动土压力强度、中间被动土压力合力和中间被动土压力系数的理论公式.分别计算分析填土为干砂及填土为饱和砂土的模型试验,与实测数据进行对比,发现两者结论比较吻合.在平动模式下,中间被动土压力与被动土压力系数均随着位移的发展而增大,且在任一位移时中间被动土压力沿墙高近似成线性分布.

The calculation of earth pressure with non-limit displacement was studied in order to accurately design retaining wall. Passive earth pressure under the non-limit state was defined as inter-mediate passive earth pressure. The failure mechanism of soil was analyzed, and the relationship between the friction angles and the wall movement was obtained. The Coulomb theory was improved. The theoretical formulas of inter-mediate passive earth pressure intensity, resultant force and coefficient with translation mode of retaining wall were derived according to the conditions of static equilibrium. Model tests which fillings were dry sand or saturated sand were both analyzed. The calculated values accorded with the measured data. Inter-mediate passive earth pressure and coefficient simultaneously increase with the displacement increases in translation mode. The distribution of inter-mediate passive earth pressure is almost linear along the wall.