既有地下室外墙影响下的挡土结构非极限主动土压力计算方法

Calculation Method for Non-limited Active Earth Pressure of the Retaining Structures Under the Influence of Basement's External Wall

针对挡土结构土压力与位移之间的关系,提出一种适用于既有地下室外墙影响下的挡土结构非极限主动土压力计算方法。基于卸荷路径推导了土体力学参数与位移的关系和考虑土拱效应下的非极限主动土压力系数;运用应力状态法和静力平衡法给出既有地下室外墙影响下的非极限主动土压力统一解;通过与室内相关模拟试验对比,采用应力状态法得到的结果较静力平衡法更接近于实际;基于挡土结构非极限主动土压力变化规律,讨论了位移比、两墙间距、墙土摩擦角、黏聚力等参数对土压力分布、合力及倾覆力矩的影响,揭示了既有地下室外墙影响的非极限主动土压力变化规律。

In order to research the relationship between pressure and displacement of retaining structure, a method for calculating the non-limited active earth pressure of retaining structures under the influence of the external wall of basement was proposed. Based on the unloading path, the mechanical parameters of soil and the displacement relationship and the non-limited active earth pressure coefficient were deduced. Then, the stress state method and the forces equilibrium method were used to solve the non-limited active earth pressure, and the comparison with the indoor physics experiments showed that the results of the stress state law were relatively closer to reality than forces equilibrium method. Based on the variation of active earth pressure of retaining structure, the influence of displacement ratio, two walls pacing,wall friction angle and cohesive force on earth pressure distribution, resultant force and overturning moment were discussed.