埋入式抗滑桩支护边坡稳定性分析

为研究埋入式抗滑桩在滑坡治理中的适用性,总结前人经验并经大量现场调查研究,提出埋入式抗滑桩支护的3种失效模式,即桩后滑体整体失稳、桩顶滑体越顶失稳和桩前滑体滑移失稳;并从失效模式入手,简化埋入式抗滑桩支护边坡稳定性分析模型。结合定点剪出的破坏假定,用传递系数法分别验算桩周3部分土体即桩后土体、桩顶土体和桩前土体的稳定性。最后在埋入式抗滑桩支护边坡稳定性分析模型的基础上,围绕滑体几何形态、滑面倾角、滑带及滑体力学性质等关键因素,对埋入式抗滑桩的适用条件进行探讨。研究表明:埋入式抗滑桩置于平缓段有利于其阻隔作用的发挥,保证桩前滑体的稳定性;置于滑体强度大于滑带强度的滑坡,有利于利用滑体较高的土工参数;置于坡面平缓的滑坡,有利于桩顶滑体的稳定。

Analysis on Landslide Stability Supported by Embedded Anti-slide Piles

For the applicability research of embedded anti-slide pile,according to the predecessors’ experience and a lot of field investigation and studies,three instability models of embedded anti-slide pile’s support,namely,instability of sliding body at the rear of the pile,instability of sliding body upward to the top of the pile and instability of sliding body in front of the pile are proposed.According to the instability models of support,a new simplified stability calculation model is put forward.Sliding body around embedded anti-slide pile is divided into three parts,i.e.sliding body at the rear of the pile,sliding body upward to the top of the pile and sliding body in front of the pile.In combination of the assumption of specified shear opening’s failure,the stability of three parts of sliding body around the anti-slide pile is computed by transfer coefficient method.Finally,based on the stability analysis of embedded anti-slide pile models,according to the key ingredients,i.e.geometric shape,slide surface angle and landslide physical properties,the applicability research of embedded anti-slide pile is discussed.The investigation results show that embedded anti-slide piles fixed on gentle period of sliding surface are conducive to barrier action function,and ensure the stability of pile-front landslide;embedded anti-slide piles fixed on the slippery body which sliding body strength is greater than sliding zone strength can effectively use slippery body’s higher geotechnical parameters;embedded anti-slide piles fixed on gentle slope surface are conducive to the stability of pile-top landslide.