高川陈家坡滑坡的形成机制及稳定性评价.doc

1 高川陈家坡滑坡的形成机制及稳定性评价摘要: 在对陈家坡滑坡进行现场地质勘查、现场试验及室内试验的基础上, 详细阐述了滑坡基本特征、分析了其形成机制与演化过程。并用极限平衡法和数值模拟法对该滑坡在不同工况下的稳定性进行计算和评价。研究结果表明: 天然状态下处于稳定状态,稳定性系数为 ;暴雨状态下处于欠稳定状态,稳定性系数为 ;地震状态下(Ⅷ级) 处于基本稳定状态,稳定性系数为 。两种方法计算滑坡稳定系数结果是基本一致的。关键词: 陈家坡滑坡; 高川乡; 滑坡特征; 形成机制; 稳定性评价 Formation Mechanism and Stability Evaluation of Chenjiapo Landslide in Gaochuan County CHEN Gang 鍄 1,LI Shi-min 鍄 1,CAI Min 鍄2 ( and Hydrology Engineering College,HefEi University of Technology,HefEI 230009,China; Vocational School of Water Resources and Hydropower,Hangzhou 310018,China ) Abstract: Based on geological investigation,field tests and 2 laboratory tests for Chenjiapo Landslide,the paper elaborated the basic characteristics of landslide,its formation mechanism and ,the slide stability under different working conditions was calculated and evaluated by limit equilibrium method and numerical results show that the landslide is in the steady state under the natural state,and its stability coefficient is ;the landslide is in the less stable state under rainstorm state,and its stability coefficient is ;the landslide is in the basically stable state under seismic loading with magnitude VIII,and its stability coefficients is result of stability coefficients obtained by limit equilibrium method and numerical simulation are mostly consistent. Key words: Chenjiapo Landslide;Gaochuan County;landslide characteristics;formation mechanism;stability evaluation 512 汶川大地震在四川全省诱发了大量的滑坡、崩塌、地面塌陷等次生地质灾害或产生新的地质灾害隐患点, 经初步排查,共诱发山体滑坡 9 326 处,造成了巨额损失。是我国建国以来破坏性最强、波及范围最广的一次地震[ 1]。陈家坡滑坡位于安县高川乡二郎村 5 组(见图 1) ,距离安县 50 km 。 512 地震当时, 坡体发生滑动, 造成前缘房屋倒塌破 3 坏,严重威胁坡脚处居民生命及财产安全。 1 滑坡的地质环境条件蕌滑坡区属龙门山中山地貌, 山体走向北偏东 122 ~ 125 。区内山势高耸, 谷坡陡峻, 梁顶圆缓, 局部形成陡崖。滑坡区由于受干河子、茶坪河、苏包河树枝状水系的切割, 山体完整性受损。该区属中亚热带湿润季风气候区,气候温和, 雨量充沛;多年平均气温 ℃,极端最高气温 ℃, 最低- ℃。年均降雨量 1 261 mm 。蕌调查资料显示,陈家坡滑坡周界呈圈椅状(见图 2), 后缘至坡顶分水岭,高程 1 155 m ,前缘潜在剪出口位于居民房后陡坎处,高程 992 ~1 000 m 。失稳方向 122 左右,与主滑方向基本一致。横