摘要
大光包滑坡是5·12汶川地震触发的规模最大的滑坡。滑坡的形成机制和运动学特征引起国内外学者的广泛关注。本文基于滑坡体运动-堆积特征的现场调查与分析,对滑坡的运动学特征进行了系统的阐述。为了再现滑坡的破坏和运动过程,应用物理模拟试验方法进行了对比研究。(1)通过对滑坡擦痕、标志性地物、滑坡堆积体植被、坡表块石倾向、滑坡裂缝、以及其他滑坡典型运动特征调查与分析研究,确定了滑坡的滑动方向、滑动距离、运动速度、运动特征值等滑坡运动特征参数,并系统地论述了滑坡扬尘、滑坡气浪、滑坡舌前缘岩性混杂堆积带以及滑坡碎屑流等典型运动-堆积现象的形成机理;(2)滑坡运动过程物理模拟试验表明,大光包滑坡破坏运动过程中存在前缘锁固段岩体剪断迸射、滑坡气浪、滑坡扬尘和"急刹车效应"等地质现象,且滑坡运动过程具有显著的阶段性;(3)大光包滑坡的运动过程可以概括为以下4个主要阶段,即:快速启动→高速滑动→"急刹车"制动→拆离滑动。
Daguangbao landslide is the largest landslide triggered by the Wenchuan MS8. 0 Earthquake on May12,2008. Its formation mechanism and kinematics attract a remained and wide attention of scholars at domestic and abroad. The paper is based on summary analysis of the engineering geological survey on the movement characteristics of landslide. The kinematics characteristics of the landslide is studied systematically. In addition,in order to reproduce the logical phenomenon in the process of sliding,physical model simulation is conducted for comparison. The results show the follows. The investigation and analysis of the slickenside,iconic features,vegetation,flat stone trend,slide cracks,and other topic features of the landslide accumulation determines the sliding direction, distance, velocity, motion eigenvalues and other movement characteristic parameters. The formation mechanism of landslide dust,blast shockwave,mixed lithology belt in the leading of slide tongue and clastic flow are systematic discussed. Landslide movement process physical simulation test confirms that Daguangbao landslide movement process has geological phenomenon such as cutting through of the front locking secting andenjection,blast shockwave,dust,'suddeyly braking ',significantly movement stage. Basically,its movement process can be dived into the following four stages,from quickly launching to high-speed sliding to 'suddenly braking'and napping motion to detaching sliding on both sides of the accumulation.
出处
《工程地质学报》
CSCD
北大核心
2015年第5期866-885,共20页
Journal of Engineering Geology
基金
国家自然科学基金项目(41572302)
地质灾害防治与地质环境保护国家重点实验室团队课题(SKLGP2012Z001)
四川省科技创新团队项目(2011JTD012)资助
关键词
大光包滑坡
运动过程
急刹车效应
物理模拟
滑坡擦痕
Daguangbao landslide,Movement process,Suddenly braking effect,Physical model simulation,Slickenside
