山区公路岩土复合型高切坡稳定性分析

Analysis on Stability of Rock-soil Composite High-cutting Slope along Highway in Mountainous Area

山区路基开挖易形成岩土复合型高切坡,其破坏机制和稳定性分析通常当作单一岩质或土质边坡进行处理,并造成治理缺乏针对性和有效性。基于岩土复合型高切坡特点,将其破坏模式归纳为上部土体内部破坏、上部土体沿土岩界面破坏、下部岩层平面滑动、下部岩层倾倒破坏四种类型,进而提出了岩土复合型高切坡稳定性分析流程,并通过重庆某主干道山区公路工程算例进行了验证。结果表明:在对边坡进行优化设计的基础上,其稳定性能满足《建筑边坡工程技术规范》的要求。

Subgrade excavation in mountainous area makes rock-soil composite high-cutting slope easily,and the failure mechanism and stability analysis thereof are always made by taking it as rock or soil slope only,thus the countermeasures are deficient in pertinency and availability. Based on the features of such composite slope,the failure modes were generalized and classified into four types： internal failure in upper soil mass,instability of upper soil mass at rock-soil interface,planar sliding and toppling of lower rock strata,and the procedure for the stability analysis herein was further proposed, and then verified through the engineering example of a main highway in mountainous area in Chongqing. The result shows that, depending on the optimized design on slope,the stability may meet the Technical Code for Building Slope Engineering.