抗滑桩阻力上下限解法

基于工程上常用的Janbu普遍条分法(GPS)和剩余推力法,提出了确定单排或多排抗滑桩抗滑阻力的上、下限计算方法。该法假定桩前、桩后滑动土体具有不同的稳定性系数,或假定桩前、桩后滑动土体具有不同的剩余推力,并且抗滑桩承受的下滑力是水平距离的函数。对于单排桩,借助于下限法可以通过试算确定其设桩范围;对于多排桩,借助于上限法可以通过有限的组合枚举确定其最佳的配置。上、下限法的结合可以巨大降低计算量,同时又能满足工程精度要求。运用该方法还可以确定不宜设置抗滑桩的位置范围。文中的算例展示了该方法的具体运用过程。

An analytical method of the stabilizing force of piles for landslide control using Janbu’s generalized procedure of slices

Based on Janbu’s generalized procedure of slices (GPS) and the residual thrust method,this paper has presented a simplified calculation procedure, including upper bound method and lower bound method, for estimating the deterrent force induced by stabilizing piles in a landslide. The lower bound method assumed that sliding masses above and below each row of piles are allowed to have different values of residual thrust force or the factor of safety, and that the thrust force is a function of horizontal position. For a single row of piles, the optimization position for pile to be exerted in can be obtained by the lower bound method by trial calculation; for multiple rows of piles, the optimization configuration of the stabilizing piles can be determined by the upper bound method by limited enumeration. The combination of the two methods is greatly able to reduce computational effort for estimating the stabilizing effect without losing largely computational accuracy. It has been illustrated through an example problem that it will have better effect to using multiple rows of piles than single rows to control a large landslide. The presented systematic method can account for all available information of different stabilizing measures in an uniform frame using Janbu’s GPS.