考虑土拱效应和平移的刚性挡土墙被动土压力

Passive earth pressure on rigid retaining wall in case of taking soil arching effect and translation mode into consideration

根据土拱效应原理,得到考虑填土内摩擦角和墙土摩擦角的平移模式下挡土墙的被动滑裂面倾角和侧向被动土应力系数,并将其用于水平微分层法的平移模式下的刚性挡土墙墙背被动土应力的分析中,得到被动土应力、被动土压力及其作用点的计算公式,并与朗肯理论、库仑理论、吴明法、侯键法、模型试验数据进行比较分析.结果表明:本文方法得到的平移模式下刚性挡土墙墙背被动土应力分布与模型试验结果吻合最好,且偏于安全的;被动土应力随填土内摩擦角的增加而增加,在墙顶附近随墙土摩擦角的增加而减小,在墙中下部却随墙土摩擦角的增加而增加;被动滑裂面倾角随墙土摩擦角增大而增大,随填土内摩擦角增大而减小.

Based on the principle of soil arching effect, expressions of passive angel of failure surface and coefficient of passive earth stress were obtained when the translation mode of wall-soil friction angel and backfill internal friction angle is taken into consideration. The presented expressions were used to analyze the passive earth stress on rigid retaining wall under translation mode with horizontal differential layer method and the computation formulas of passive earth stress, passive earth pressure, and its applying point were derived and compared with the theoretical solutions of Coulomb, Rankine, Wuming, Houjian, and the model experimental data. Results showed that the distribution of passive earth stress in wall back of rigid retaining wall with translation mode obtained with the method of this article would be accordant well with that of model test, having bias towards more safe. With the increase of the backfill internal fric- tion angle, the passive earth stress would increase, but decrease with wall-soil friction angle near the wall top, and increase at the bottom in the walt. With the increase of the wall-soil friction angel, the passive angel of failure surface would increase, but decrease with backfill internal friction angle.