基于离散元的碎裂岩质边坡卸荷松弛特征研究

Study on Unloading and Relaxation Characteristics of Cataclastic Rock Slope Based on Discrete Element Method

边坡卸荷松弛特征对边坡稳定性具有重要影响。采用颗粒流法模拟碎裂岩质边坡卸荷全过程,探讨卸荷过程中能量、位移的时空演化规律。基于PFC模拟和探地雷达探测提出一种新的卸荷分区判定方法。研究结果表明:边坡卸荷过程能量经历骤变、波动、平稳3个过程,外力功大多以应变能的形式存储在岩体中;边坡平均卸荷深度达2 m,探地雷达在边坡卸荷区检测中具有良好的适用性;基于边坡变形特征和探测结果,将边坡分为开挖损伤区、卸荷影响区和轻微扰动区。

The influence of slope unloading and relaxation characteristics to slope stability is very important, the particle flow method（PFC） is adopted to simulate cataclastie rock slope unloading process, to discuss the evolution rules of energy and displacement. A new division unloading method is proposed based on PFC simulation and ground penetrating radar（GPR）. The results show that the energy in the process slope unloading experiences three segments （ thrust deformation stage, fluctuation de- formation stage and stationary deformation stage） ,the external work is stored with the ore mass form with the form of strain energy ; the average unloading depth is 2 m, the applicability of GPR in the detection of slope unloading area is good. Based on the characteristics of slope deformation and detection results, the slope is divided into the excavation damage zones, unloading effect zones and slight disturbance zones.