土石混合体中抗滑桩抗滑力计算方法

A Method of Calculating Sliding Resistance of Anti-sliding Pile inSoil-Rock Mixture

抗滑桩是加固堆积层滑坡的主要工程措施之一,其与滑坡体的相互作用力决定了滑坡加固效果。堆积层滑坡多由土石混合体构成,为计算土石混合体中抗滑桩的抗滑力,引入土石混合体宏观抗剪强度指标评价模型,基于桩间土拱效应,构建了考虑块石体积含量(含石量)及休止角的抗滑力计算方法,并提出土石混合体中抗滑桩抗滑力的计算流程。针对20%~45%含石量和25°~40°休止角的土石混合体研究发现,土石混合体中抗滑桩提供的抗滑力并不总是大于纯土体中抗滑桩提供的抗滑力,其相对关系取决于块石的含石量与休止角的数值,并且存在明显的分界线。通过与数值模拟结果对比,验证了本文抗滑力计算方法的合理性,为堆积层滑坡中抗滑桩抗滑力的初步计算提供了一种可行的方法。

Anti-slide pile is a major engineering measure to reinforce debris landslide.The interaction between anti-slide pile and sliding mass determines the reinforcement effect.Debris landslide is mostly composed of soil-rock mixture.A model for evaluating the macro-shear strength index of soil-rock mixture is introduced to calculate the sliding resistance of anti-slide pile in soil-rock mixture.A method of calculating sliding resistance in consideration of volumetric block proportion(VBP)and angle of repose(δ)is presented based on the theory of soil arch between piles.The design procedures of anti-sliding pile in soil-rock mixture are also proposed.According to the study of soil-rock mixture with a VBP of 20%~45%andδof 25°~40°,the sliding resistance provided by anti-slide pile in soil-rock mixture is not always greater than that in soil.The safety of anti-slide pile depends on the value of VBP andδ,with a clear dividing line.Comparison with numerical simulation results verifies the rationality of the present method.