刚性挡墙绕底转动时的非极限主动土压力数值解北大核心CSCD

刚性挡土墙在下部受限时往往呈现绕墙底转动的位移模式,该模式下不同深度土体所处非极限状态不同,给土压力计算带来了困难.在已有研究基础上,推导了适用于绕墙底转动模式下土体强度参数与墙体位移的函数关系;假定墙后土体形成圆弧形土拱,滑裂面为不确定的曲面,将墙后土体按小步长水平分层,构建了绕墙底转动模式下非极限主动土压力的数值迭代格式,给出了该模式下非极限主动土压力的数值计算方法.该数值解既能确定墙后滑裂面的形状,又能计算非极限主动土压力的强度、合力及作用点.将数值解与模型试验结果、现有解析解进行了对比,发现墙后滑裂面为一曲面,该解计算结果与模型试验结果的契合度比现有解析解更高.这提供了刚性挡土墙绕底转动时非极限主动土压力的更精确解答,对这类挡土墙设计具有现实指导价值.

Numerical Solutions of the Nonlimit-State Active Earth Pressure Under Backfill Wall Rotation Around the Bottom

The displacement pattern of wall footing rotation occurs for the backfill wall constrained at the bottom. The non-limit states of the soil layers at different depths are different in this pattern, and present difficulties for soil stress calculation. Based on the existing research, the functional relationship between soil strength parameters of the wall footing rotation pattern and wall displacements were detruded. Under the assumption that the backfill forms a circular arch and the slip surface is uncertain, the backfill was divided into long horizontal slices, the numerical iteration scheme for the nonlimit-state active earth pressure in the wall footing rotation pattern was constructed, and the numerical calculation method for the active earth pressure was given. The numerical method not only determines the slip surface shape, but calculates the intensity, the resultant force and the action point of the nonlimit-state active earth pressure. The backfill slip surface is a curved one and the new numerical solution is more consistent with the existing full-scale test results than the existing analytical results. This work provides more accurate numerical solutions of the nonlimit-state active earth pressure on the rigid retaining wall in the footing rotation pattern, and makes a practical guide to design of such retaining walls.