双排抗滑桩加固滑坡的前桩后侧推力算法

A calculation method for thrust on the fore piles of double-row stabilizing piles used to reinforce landslides

为了在求解双排全长桩和后排沉埋-前排全长桩中前桩后侧坡体推力的同时也可得到其分布模式,以便更合理确定前排桩受力特征,针对双排桩加固的基岩-覆盖层式滑坡,采用斜条分法将排间滑体分割成若干斜向平行滑面的土条;对所形成的在不同深度位置的4类典型土条,根据静力平衡条件,推导了其作用于前桩受荷段后侧的推力计算公式,进而可确定出前排桩受荷段后侧坡体推力分布模式及其合力。实例分析表明,本文方法所确定的前桩后侧坡体推力呈不规则抛物线形分布,其峰值点接近于滑面;后排桩沉埋模式时前桩后侧坡体推力比后排桩全长模式时的值小8.6%~10.6%;本文方法比传递系数法的计算值偏大10.6%~13.4%,且相对更接近于FLAC3D模拟结果。

In order to better understand the thrust and its distribution pattern on the fore piles of double-row fulllength piles and embedded rear-row piles combined with full-length fore-row ones used to reinforce landslides,an inclined slice method is provided in this article.The slide mass between the two pile-rows is divided into many oblique slices parallel to the local slip surface.These slices are involved in four basic types at various depths.Calculation formula of the thrust of each inclined slice on the loading segment of the fore pile can be derived based on the static equilibrium principle,and the distribution pattern of the thrust and its resultant force can be determined.The analysis results of the examples indicate that the thrust on the fore pile determined by the proposed method shows approximately parabolic distribution and its peak point is close to the slip surface.The calculated thrust on the fore piles under the embedded rear-row piles are 8.6%to 10.6%smaller than that under the full-length rear-row piles.The proposed thrusts are about 10.6%to 13.4%higher than those by the classical transfer coefficient method,and are relatively close to the numerical results via FLAC3D.