柔性桩黏性土的非极限主动土压力
Active earth pressure of cohesive soil against flexible pile under nonlimit state

以柔性桩支护的黏性土基坑边坡为研究对象，考虑桩后土拱效应、非极限状态下桩土内摩擦角和黏聚力发挥值、桩后土体内摩擦角和黏聚力发挥值的影响，从黏性土应力莫尔圆出发，采用微层分析法建立静力平衡，搜索桩后土体潜在滑动面，推导柔性桩黏性土的非极限主动土压力计算式。通过实例计算对比分析了本文计算理论与经典Rankine计算理论，本文计算方法计算得到的主动土压力大于Rankine计算值，合力作用位置高于Rankine计算值，潜在滑动面范围小于Rankine极限状态滑动面。
Considering soil arching effects, the internal friction angle and cohesive force between pile and soil, between soil particles are generally under nonlimit state. Cohesive soil slope supported by flexible pile is studied and the potential slope sliding surface is searched and the formulas of the active earth pressure of cohesive soil under nonlimit state against flexible pile is derived via Mohr circle of stress, micro layer analysis method as well as the static equilibrium. The difference between the theory proposed and Rankine solution is studied via comparison with engineering applications. The active earth pressure calculated by proposed method in this paper is greater, while the location impacted by resultant force of the active earth pressure is higher. Besides, the ranse of potential sliding surface is smaller than that of sliding surface under Rankine limit state.