基于数值仿真的全强风化岩质边坡失稳机制研究

Numerical Simulation of Failure Mechanism of Fully-highly Weathered Rock Slope

利用数值分析方法来分析边坡的稳定性正逐渐被人们所重视。以某公路边坡工程为例采用考虑地形变化的极限平衡法和考虑变形发展过程的有限元强度折减法相结合的方法对全强风化岩质边坡的失稳机制进行了研究。研究结果表明:边坡的失稳破坏机制表现为典型的牵引破坏,全强风化岩体遇水容易软化,边坡中前部抗滑段饱和时会导致岩体强度极大下降,对于边坡的稳定十分不利,中前部边坡失稳导致滑坡逐渐向上发展,牵引逐级发育,前一级潜在破坏为后一级的发展提供了临空空间。针对这种失稳机制,建议工程措施应重视阻滑段的疏排水,通过工程加固手段阻止第一级破坏发生。

Numerical simulation method for slope stability analysis has been paid more and more attention. In this paper the mechanism of slope instability destruction of fully-highly weathered rock mass was investigated based on limit equilibrium method considering topographic development and strength reduction finite element method considering deformation development. It was found that the strength of fully-highly weathered rock mass can be easily softened by water. Great reduction of strength was caused when the front anti-sliding segment was in saturation, which played a key role in the slope stability. The failure mechanism of retrogressive landslide was appeared in the process of slope instability, and the traction developed upwards step by step, which provided the space for deformation. Therefore the first level damage should be prevented and drainage measures should be highly regarded.