顺层震裂斜坡降雨触发灾变机制及稳定性分析——以三溪村滑坡为例  

Disaster mechanism and stability analysis of shattered bedding slopes triggered by rainfall——a case study of Sanxicun landslide

作　　者：冯文凯[1] 胡云鹏[1] 谢吉尊 王琦[1] 吴刚[1] FENG Wenkai HUYunpeng XIE Jizun WANG Qi WU Gang(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, Siehuan 610059, China)

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,四川成都610059

出　　处：《岩石力学与工程学报》2016年第11期2197-2207,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(41572291)~~

摘　　要：震裂斜坡作为震后灾区潜在的高危地质灾害承载体分布广泛,尤其在雨季突发失稳的现象突出。针对该类灾害,以三溪村滑坡为例,通过现场详细调查,采用Seep模块探寻降雨作用下斜坡的水响应规律,并通过室内试验获取不同条件下的强度参数。在此基础上,对降雨触发型震裂斜坡变形破坏的机制模式进行归纳,参照滑坡所处实际情况建立相应的水力学模型,量化计算斜坡稳定性系数。研究表明:(1)顺层震裂斜坡灾变过程可分为原始斜坡–地震损伤–蠕变弱化–降雨触发–滑坡失稳5个演化阶段。(2)降雨是岩体形成深部裂隙、节理扩展从而切割岩体呈条块状的重要原因,同时裂隙的贯通促进了降雨入渗,导致滑带饱水软化、加速蠕变变形至失稳。(3)降雨与震后蠕变效应的耦合作用是影响坡体稳定性的主要因素,经历前期的降雨饱水软化以及同期的蠕变累计变形,最终在暴雨形成的水动力触发下失稳破坏。研究成果为降雨型震裂斜坡稳定性机制分析及工程治理提供参考。Widely distributed shattered slopes are potentially high-risk carriers of geological disasters in earthquake areas especially in the rainy season. A slope in Sanxicun was studied as an example in this paper. Based on the detailed site investigations,the effect of rainfall was investigated with the Seep model. The strength parameters under different conditions were acquired in the laboratory tests. The deformation and destructive mechanism of the shattered slope triggered by rainfall were summarized. The slope stability in the light of the actual situation and the corresponding mechanical model was calculated. The sliding process of the shattered bedding slope was divided into five stages such as the original status,earthquake damage,creep weakening,rainfall triggering and sliding. Rainfall was found to be the main reason to form deep cracks,expanding joints and massive rock strips. At the same time,the cracks promote the rainfall infiltration,resulting in water softening,creep deformation and finally sliding. The main factor to affect the stability of the slope is the interaction of rainfall and creep after the earthquake.

关 键 词：边坡工程 震裂斜坡 降雨 蠕变 灾变机制 

分 类 号：P642[天文地球—工程地质学]