基于墙后土体滑裂面的朗肯被动土压力的探索

Exploration of Rankine Passive Earth Pressure Based on Sliding-cracking Surface of the Soil Behind the Wall

基于前人从极限平衡理论出发而提出的朗肯土压力作用下的极限土体会出现滑裂面这一前提,推导了墙背与土体之间的摩擦力作用下墙背垂直的挡墙和仰斜式挡墙的朗肯被动土压力的公式,列表分析了墙背垂直挡墙的外摩擦角对墙后土体破裂角和朗肯被动土压力的影响,并对比分析了仰斜式挡墙的倾角对墙后土体破裂角和朗肯被动土压力的影响,在举例过程中也侧面印证了通过求导数计算被动土压力时应该取破裂角变化范围内的极小值。另外,通过公式对比及理论分析,提出了墙背与土体之间外摩擦角的两种简便可行的理论测定方法。

Based on the premise that the limit soil mass can produce sliding-cracking surface under the influence of Rankine earth pressure proposed by the former according to limit equilibrium theory,vertical and inclined retaining wall’s Rankine passive earth pressure under the action of friction force between the wall back and the soil mass is derived,the influence of vertical retaining wall’s external friction angle on cracking angle and Rankine passive earth pressure is analyzed by listing the table.The influence of inclined retaining wall’s dip angle on cracking angle and Rankine passive earth pressure are also contrasted and analyzed by listing the table.In the process of giving examples,it is also verified that the minimum value within variation range of cracking angle should be taken when passive earth pressure is calculated by the derivative.In addition,two simple and feasible theoretical methods about the external friction angle between the wall back and the soil body are proposed by the formula comparison and theoretical analysis.