堆积体边坡碎石土抗剪强度试验研究

基于大型室内直剪试验结果，对含石量及含水量分别与堆积体边坡碎石土黏聚力及内摩擦角的关系进行了深入研究。结果表明：碎石土黏聚力的大小随着含石量的增加，表现出先逐渐增大后减小的趋势，内摩擦角随着含石量的增大表现出逐渐增大的趋势；黏聚力随含水量的增大有一定程度的增大，超过碎石土中细粒土塑限含水量后逐渐减小。基于试验结果，将碎石土的黏聚力表示为含水量与含石量的二元函数，并提出了考虑饱和度与基质吸力影响的碎石土的抗剪强度公式，将有助于准确评估降雨作用下碎石土边坡的稳定性。

Experimental Study on Shear Strength of Rock-soil Aggregates in Accumulation Slope

Based on the large-scale direct shear test results of rock-soil aggregates in accumulation slope ,the relationship between cohesion and gravel content,between friction angle and gravel content, and the relationship between cohesion and water content,between friction angle and water content,is studied in this paper.The results show that the cohesion increases at first and then decreases as gravel content increases,the friction angle increases as gravel content increases.The cohesion increases as water content increases before the water content reaches plastic limit,and when its water content beyond plastic limit cohesion decreases;the friction angle decreases as water content increases,and it decreases obvi-ously when fine stuff water content is 15%~20%.Based on these results,the shear strength formulation of rock-soil aggregates that could consider suction and saturation degree influence is put forward in this paper,which would contribute to accurate evaluation of the stability of accumulation slope under rainfall condition.