考虑摩擦条件下临近既有建筑物的有限土体土压力上限解

针对现有刚性挡土墙与支护结构工程有限土体土压力研究大都基于墙背光滑的假定，本文考虑挡土墙与填土之间及建（构）筑物与填土间的摩擦作用，挡土墙背倾角及填土顶面竖向荷载的影响，引入极限分析上限理论进行研究。根据临近建（构）筑物有限宽度土体的工程特性，基于平动模式采用直线滑动破裂面，在土压力上限求解中引入粗糙挡土墙及粗糙建（构）筑物与土界面间的摩擦能耗计算，分别建立有限宽度土体在主动极限状态和被动极限状态下的土压力计算模型，并利用数值计算方法求解。通过对有限土体主动土压力进行参数分析，表明极限破裂角是一个不确定角，其随着计算深度增大而非线性增大，随有限土体宽度和挡土墙背倾角增大而减小；主动土压力合力随墙土间外摩擦角、挡土墙背倾角及超载增大而增大，墙土间外摩擦角对极限破裂角影响较小，而对土压力合力影响较大。通过工程算例分析并与其它方法计算结果进行对比，表明有限土体主动土压力和被动土压力均小于无限土体土压力。

Upper bound solution of earth pressure for limited soils adjacent to existing buildings considering friction energy consumption

Limited soils are widely uses in all kinds of rigid retaining wall and supporting structure engineering and the assumption of smooth wall are adopted in the existing research methods for the limited earth pressure. In this paper, the theory of upper limit analysis is introduced, and the linear sliding failure mode is established according to the engineering characteristics of finite width of soil adjacent to building (structure). The friction energy consumption of the interfaces between the wall and soil are calculated, and the earth pressure computation models are put forward respectively as active or passive limit equilibrium state, which can reflect the influence of the friction and the retaining wall back angle and the vertical load. The results show that the limit rupture angle is not constant and it varies with the calculation parameters based on the analysis of limited active earth pressure. It increases nonlinearly with the increasing computing depth, and decreases with the limited width of soil and the increasing retaining wall back angle. The active earth pressure resultant force increases nonlinearly with the external friction angle, the retaining wall back angle and the increasing overload. It is also shown that the limited active earth pressure and passive earth pressure are less than the infinite earth pressure by comparison with current research results.