吉牛水电站顺层岩质边坡变形体成因机制及防治效果分析

Analysis on the Genetic Mechanism of Deformation Body and Prevention Effect in Bedding Rock Slope of Jiniu Hydropower Station

顺层岩质边坡往往在坡脚进行工程开挖后诱发滑坡等地质灾害,一般采用锚索、抗滑桩等进行防治,但其治理效果如何通常难以检验。以吉牛水电站开挖后的顺层岩质边坡为例,结合变形体的地质条件、变形破坏特征、监测数据等资料,采用离散元数值模拟计算方法,分析不同工况条件下的滑坡变形响应过程、基本破坏规律,确定其主要诱发因素及形成机制,并结合防治方案进一步检验治理后的防治效果。研究结果表明,该滑坡为一处主要由前缘开挖诱发的滑移-拉裂式滑坡,并根据其破坏模式和地形地质条件采用深层锚索、中层锚筋束、浅层锚杆、表层喷护等深浅层结合手段进行综合加固。数值模拟结果与实际监测数据均显示变形趋势得到有效控制,工程防治效果良好,对类似的其他工程具有一定指导意义。

The bedding rock slope often induces landslide and other geological disasters after engineering excavation at the foot of the slope.Generally,anchor cables and anti slide piles are used for prevention and control,but its control effect is usually hard to test.Taking the bedding rock slope after excavation of Jiniu hydropower station as an example,combined with the geological conditions,deformation failure characteristics,monitoring data and other data of the deformation body,the discrete element numerical simulation method was used to analyze the landslide deformation response process and basic failure laws under different working conditions,determine its main inducing factors and formation mechanism,and further test the control effect after treatment in combination with the control plan.The research results show that the landslide is a sliding-tension type landslide mainly induced by the front edge excavation.According to its failure mode and topographical and geological conditions,the landslide is comprehensively consolidated by deep and shallow combined means such as deep anchor cable,middle anchor tendon,shallow anchor bolt and surface shotcrete.Both the numerical simulation results and the actual monitoring data show that the deformation trend is effectively controlled,and the engineering prevention effect is good,which has certain guiding significance for other similar projects.