临近地下室边墙挡土墙主动土压力解析解

Analytical Solution of Active Earth Pressure Behind Retaining Wall Adjacent to Existing Basements Exterior Wall

随着工程建设的需要,特别是在临近地下室边墙修筑挡土墙时以半无限土体为基本假设的传统土压力计算公式不再满足需求。针对此类问题,以平面滑裂面为假设,将墙后土体分为上下两个隔离体,采用薄层单元法推导了临近地下室边墙挡土墙主动土压力计算的解析公式。公式考虑了墙土间黏聚力和摩擦角的影响,在特定条件下现行的土压力公式为特解,从而论证了计算方法的正确性。计算得到的黏性土极限破裂角不为定值;随着计算参数的变化而呈现不同的变化特征,因此在土压力求解时须重新计算破裂角。通过算例分析表明:在考虑墙土内聚力和摩擦角情况下,主动土压力明显小于朗肯解和文献解,其结果对实际工程有一定的参考价值。

With the development demand of construction,it was inconsistent with the traditional theory of soil pressure which was based on the semi-infinite half space state,specially construting a retaining wall adjacent to existing basements.For such problems,based on plane slip surface,the analytical formula is derived by using the thin-layer element method.The cohesion and internal friction angle between wall and soil was considered by this formula.Meanwhile it was proven that the prevailing classical earth pressures were special examples simplified under the condition of their assumptions,respectively.But the angle of cohesion soil s shear failure is not constant and varies with the calculation parameters,so the angle must be re-solved when the caculation of earth pressure is done.According to the examples,the results by proposed method are much less than the other results and close to the simulation results.So it has a significant meaning for active earth pressure theory.