老鹰岩滑坡成因机制与运动特征研究  

MOVEMENT CHARACTERISTICS AND MECHANISM OF LAOYINGYAN LANDSLIDE TRIGGERED BY WENCHUAN EARTHQUAKE

作　　者：裴向军[1] 郝永峰 张军新[1] 袁进科[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059 [2]新疆交通建设管理局,乌鲁木齐830000

出　　处：《地质灾害与环境保护》2010年第4期28-32,共5页Journal of Geological Hazards and Environment Preservation

基　　金：国家自然科学基金项目(40972195);教育部创新团队计划(IRT0812);地质灾害防治与地质环境保护国家重点实验室自由探索课题(SKLGP2009Z009)

摘　　要：老鹰岩滑坡是汶川地震触发的大型岩质滑坡,滑坡纵长450 m,最大展宽430 m,体积约1 500×104m3。滑坡掩埋了一座中型水电站,造成20余人死亡,巨大的滑体堆积厚达100余米的滑坡坝,形成了汶川震区库容量仅次于唐家山的第二大堰塞湖。强震触发形成老鹰岩滑坡分为三个阶段,即:①后缘震动拉裂阶段。老鹰岩滑坡后缘为一突兀山脊,地形对地震动力放大效应明显,震动拉裂沿长大结构面形成了一个陡峭、粗糙,与重力作用下呈光滑、有一定弧形的后缘拉裂面迥异的边界。②摩擦阻力降低、滑体溃滑阶段。地震动力的持续作用,地震波不断在滑面处发生反射和折射,使得滑面处摩擦阻力迅速降低,进而岩体内"锁固段"剪断,滑体顺层面高速下滑。③滑体高速流动堆积阶段。规模巨大的滑体,冲入姜巴沟,并对沟两侧的山体产生强烈的铲刮,高速碎屑流受到黄洞子沟左侧山体强力阻挡后折返,并震动堆积形成堰塞湖。Laoyingyan landslide is a large rock landslide,wihch was triggered by the Wenchuan Earthquake.Its length is 450 m with 430 m max-wide,and the volume is about 1.5×10^5 m^3.The depth of the landslide deposite is over 100m,which formed the second biggest quake lake dam in Wenchuan Earthquake zone.The formation of the landslide could divided into the flowing three stages： ①The stage of shattering cracking.Shock cracking occurs within the rockmass,debacle surface formed and interconnected.Slope mass sliding constituted.②The stage of friction decrease and ＂locked section＂ snipping.Under the effection of earthquake force,seismic wave continued to occur refraction and reflection.Then declined the friction of debacle surface rapidly.The ＂locked section＂ in the landslide front was snipped sharply,while slip mass sliding along the slip surface with a high speed.③The stage of slipmass sliding-accumulating.Slip mass cracking and sliding that shaped debris flow then accumulated.

关 键 词：汶川地震 老鹰岩滑坡 成因机制 运动特征 

分 类 号：P642.22[天文地球—工程地质学]