不同形式节理的岩质边坡失稳演化离散元分析

Distinct Element Method Analysis of the Failure Evolution of Rock Slope with Different Types of Joints

摘要:

为研究不同形式的节理边坡的破坏机理，将考虑胶结尺寸的微观接触模型植入离散元软件，基于重力增加法实现边坡失稳演化过程的模拟，从边坡形态、胶结破坏分布、滑体运动等方面进行分析.模拟结果表明,顺层岩质边坡为共面节理发生贯通破坏形成滑动面，反倾岩质边坡为非共面节理发生贯通破坏形成滑裂面；两种岩质边坡坡脚均为薄弱区，顺层岩质边坡坡面中部区域和反倾岩质边坡坡肩区域为危险区域；离散元模拟岩质边坡可用安全系数评价边坡稳定性，较极平衡法能更真实地反映岩体间的相互作用和边坡破坏的渐进过程.

关键词:顺层/反倾岩质边坡; 破坏演化; 离散元法

Abstract:

In order to investigate the failure mechanism of slopes with different types of joints, the contact model considering the bond size was implanted into the distinct element method(DEM) software. Based on the gravity increasing method, the failure processes were simulated, and the slope configuration, the distribution of bond breakage, and the movement of slip masses were analyzed. The results show that the sliding surface is formed from the failure of coplanar joint in the bedding rock slope, while the noncoplanar joint in the toppling rock slope. The toe of the slope is a weak area in both the bedding and toppling rock slope. Besides, the mid area near the slope surface in the bedding rock slope as well as the slope shoulder area in the toppling rock slope are flimsy. In addition, the DEM simulation is able to evaluate the stability of the slope like the limit equilibrium methods and better reflect the forces among rock fragments and the gradual failure process.

Key words:bedding/toppling rock slope; failure evolution; discrete element method(DEM)