攀西红层区大型滑坡失稳方式分析

四川攀西地区侏罗系、白垩系红层广泛分布, 其岩体结构破碎, 产状多变, 工程地质性质脆弱, 是区内主要的易滑地层。攀西红层区内滑坡发育, 灾害数量众多, 危害严重, 大型滑坡易堵塞前缘河道, 诱发严重的次级危害。本文在对区内众多大中型滑坡实地调查的基础上, 对攀西红层区内大中型岩质滑坡的失稳方式进行了分析和归纳, 为攀西地区滑坡失稳条件研究和区内的滑坡灾害防治提供了理论基础。通过研究分析, 发现攀西地区构造活动强烈, 红层区内大型滑坡发育受地质构造影响显著, 构造结构面与原生层理面形成的有利组合往往奠定了滑坡的边界, 控制了滑坡的失稳方式。依据其不同的斜坡结构特征, 攀西红层区大型岩质滑坡失稳方式可划分为平面顺向滑动、块状斜向滑动及楔形横向滑动等3种类型。

ANALYSIS ON FAILURE MODE OF LARGE-SCALE LANDSLIDES IN PANXI RED BED REGION

Jurassic formationand Cretaceous formation are widely distributed in Panxi region. The engineering geological property of red bed is bad and red bed is main sliding-prone stratum. Massive landslides develop in Panxi red bed region, its harm is serious. Large-scale landslides are easy to block rive, induce serious secondary damage. Based on the investigation of large-scale landslide, the paper systemically analyzed failure mode of large-scale landslides and it can supply theoretical support for landslide forecasting and prevention in Panxi red bed region. Through the research, we found that large-scale landslide development is significantly affected by geological structure. The favorable combination of structure planes and primarybedding surfaces lays a foundation for landslide, it controls failure mode of large-scale landslides. According to the characteristic of slope form, this paper divides failure mode of large-scale landslides in Panxi red bed region into three types, namely, consequent sliding, oblique sliding, cuneiform sliding.