基于双土拱效应的砂性土滑坡中抗滑排桩滑坡推力研究

Research on Landslide Thrust of Anti-slide Row Piles in Sandy Slope with Consideration of Double Soil-arching Effects

从产生抗滑排桩桩后滑坡推力的滑动土体作用范围出发,在莫尔圆极点理论基础上首先确定桩后砂性土滑坡的土拱效应区域.随后在库仑理论基础上推导了考虑滑坡倾角影响的库仑主动土压力系数并得出考虑土拱效应影响的桩侧土体主动水平应力作用解析表达式.结合考虑土拱效应的局部塑性变形理论改进解推导得出了抗滑排桩桩身滑坡推力分布及滑坡推力合力解析解.通过解析法、数值模拟结果分别对本文方法进行了对比分析,证明了本文所得考虑滑坡倾角影响的库仑主动土压力系数以及桩身滑坡推力解析解的正确性.最后,开展了抗滑桩桩身滑坡推力的参数影响分析,结果表明:抗滑排桩的桩身滑坡推力作用随滑坡倾角β、砂土内摩擦角φ的增加以及桩间距比值D1/d的减小而增加.

In terms of the range of sliding mass resulting in landslide thrust on stabilizing piles,firstly,this paper established the range of soil-arching effect of sandy-slope behind anti-slide piles based on the pole point theory of Mohr’s circle.Moreover,on the basis of Coulomb’s theory,the analytical solutions for Coulomb’s coefficient of active earth pressure considering the influence of slope angle and lateral stress nearby pile sides with consideration of soil-arching effect were obtained.Furthermore,the analytical solutions for distributed model and resultant force of landslide sliding force acting on anti-slide piles were obtained by adopting the improved solution of the theory of partial plastic deformation which takes account of soil-arching effect.Success of the proposed methods in this paper is illustrated by good comparison with the results of available analytical approach and numerical simulation,which verifies the correctness of the derived Coulomb′s coefficient of active earth pressure considering the influence of slope angle and analytical solution for landslide thrust on anti-slide pile.Finally,the performed parametric study on landslide thrust reveals that landslide thrust and corresponding resultant force increase with the increasing slope angleβ,internal frictionφand decreasing the ratio of D1/d.