红层滑坡变形破坏机理及稳定性分析——以采书组滑坡为例
Deformation Failure Mechanism and Stability Analysis of Red Layer Landslide—A Case Study of Caishuzu Landslide

近年来，受极端气候条件影响，红层地层中发生了较多的滑坡地质灾害，造成重大人民财产损失。本文以喜德县采书组滑坡为例，发现滑坡变形失稳破坏地质模式可分为3个阶段，即：1) 降雨促使岩土体强度降低，诱发坡体产生蠕滑拉裂；2) 滑动面裂隙贯通，呈突发“溃决”式滑动；3) 滑体迅速停止滑动，滑体解体堵江，形成堰塞湖坝。滑坡堆积体在天然工况下处于稳定状态，暴雨工况下处于欠稳定状态；后缘滑坡壁天然工况下处于不稳定状态，朝临空面产生蠕滑变形，暴雨工况下滑坡壁以及前期蠕滑变形体均处于不稳定状态，易发生失稳破坏；滑坡左侧岩质边坡整体处于稳定状态，局部受节理裂隙控制易发生崩塌掉块现象。本文通过现场调查、工程地质勘探等手段，揭示该滑坡为多种因素共同影响形成，其中降雨为主要控制因素，并且对红层滑坡变形破坏机理及稳定性进行了详细分析，为红层滑坡地质灾害防灾减灾工程提供基础支撑，以减小人民财产损失。
The landslide of Caishuzu landslide in Xide County is a typical landslide in red stratum. Through on-site investigation and engineering geological exploration, it is revealed that the landslide is caused by many factors, among which rainfall is the main controlling factor. The geological model of landslide deformation, instability and failure can be divided into three stages: 1) in the start-up stage, rainfall induced creep cracking of slope; 2) acceleration and short-range flight stages: the sliding surface runs through, showing “burst” sliding, accompanied by parabolic motion characteristics; 3) the stage of impact, disintegration and river blocking: the landslide impacts the right bank slope of the river, which disintegrates and breaks up the landslide, blocks the valley, and cuts off the flow to form a barrier lake. Landslide deposits are in stability under natural conditions and in understable state under rainstorm conditions. The trailing broken walls of landslide are in an unstable state under natural conditions and produce creep deformation toward the free surface. The landslide wall and the pre-creep deformation body are in an unstable state under rainstorm conditions, and are liable to destabilization and destruction; the rock on the left side of the landslide is in an unstable state. The quality slope is in a stable state as a whole, and it is easy to collapse under the control of local joints and cracks. This article, through field investigation and engineering geological exploration, reveals that the landslide was caused by various factors, including rainfall as the main control factors, and analyzes the landslide deformation failure mechanism and stability of the red layer in detail, providing basic support for the red layer landslide geological disaster prevention and mitigation, to minimize the loss of people’s property.