文家沟巨型岩质滑坡高速远程运移特征分析

文家沟滑坡是汶川地震诱发的巨型高速远程岩质滑坡,其运移特征尚不明确。在现场调查的基础上,结合遥感解译,进一步深入研究其运移特征。分析得出,滑体自滑源区差异性启动,途经斜坡区铲刮坡表岩土体,随后以滑行、飞行等方式进入沟谷区,沿沟铲刮两岸坡体继续下行,与岸坡发生了5次明显的冲撞,逐步解体碎屑化,于第3次冲撞后开始大规模减速堆积,最终于沟口区停积。结果表明,地形是滑体运移堆积的主控因素,滑体的解体碎屑化和冲撞山体时的爬高、抛摔、越顶现象以及冲击气浪的形成等是高速行程的具体表现,碰撞是导致全程解体碎屑化的主要途径。

SLIDING CHARACTERISTICS OF HIGH-SPEED AND LONG RUN-OUT GIANT ROCKSLIDE LANDSLIDE AT WENJIAGOU STREAM

Wenjiagou landslide is a giant rockslide with high-speed and long run-out.It was triggered by the 2008 Wenchuan earthquake.But its sliding characteristic is unclear so far.This paper presents a study on the sliding characteristic of this rockslide.It is based on the field investigation and is combined with remote sensing interpretation.The conclusions are as follows: The slip mass started diversity from source area,scraped rock-soil body of slope surface at the slope area,and then glided or flied into Wenjia gully,continued to downslide along the gully,meanwhile scraped the both valley side slopes.The rock mass occurred five times large-scale collisions with the bank slopes,disintegrated into debris gradually.The debris began to slow down and accumulate in large-scale after the third collision.Finally some sediments reached the valley mouth.The results show that,the hilly terrain is the controlling factor of sliding and accumulation of slip mass,climb,toss,overtopping of slip mass when it crashed into a hill.The disintegration into debris of slip mass and the formation of air blast were the concrete manifestation of high-speed travel.The collision was the main way leading to the disintegration of debris in the whole process.