降雨作用下考虑结构面劣化的边坡块体稳定性评价  

Stability evaluation of slope block considering structural surface deterioration under rainfall

作　　者：高丙丽[1] 韦兆恒 任建喜[1] 张路青[2] 蔡智云[3] 李铎[4] Gao Bingli;Wei Zhaoheng;Ren Jianxi;Zhang Luqing;Cai Zhiyun;Li Duo(Xi’an University of Science and Technology,Xi’an 710054,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Northwest Engineering Corpo-ration Limited,Xi’an 710065,China;China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]西安科技大学,陕西西安710054 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国电建集团西北勘测设计研究院有限公司,陕西西安710065 [4]中国地质大学(武汉),湖北武汉430074

出　　处：《土木工程学报》2024年第10期95-107,共13页China Civil Engineering Journal

基　　金：国家重点研发项目(2019YFC1509703);陕西省重点研发计划(2021ZDLGY07-08)。

摘　　要：降雨是诱发边坡失稳,发生崩塌、落石、滑坡的一个主要诱因,降雨作用下结构面强度会发生劣化,导致边坡块体失稳塌落,引起地质灾害,对人民生命财产构成严重威胁。基于离散元数值分析方法,考虑降雨作用对结构面抗剪强度的影响,分析结构面强度参数劣化及孔隙水压力变化规律,建立抗剪强度劣化模型;结合坐标投影原理提出考虑降雨作用下结构面强度劣化效应的块体稳定性系数计算方法;基于有限元分析方法研究降雨强度与降雨历时对岩质边坡块体稳定性的影响,并进一步分析稳定性系数与降雨强度及降雨历时的关系,提出降雨作用下考虑结构面劣化的边坡块体稳定性评价方法。研究表明,不同含水率作用下结构面的抗剪强度劣化不仅受黏聚力和内摩擦角影响,还与孔隙水压力有关,针对单滑面和双滑面型块体构建了考虑结构面降雨劣化的稳定性分析数学模型,提出的以降雨时长、降雨强度和块体稳定性关系曲线的共同评价体系可为边坡块体稳定性评价提供科学依据,并推动边坡地质灾害防治和工程建设发展。Rainfall is a major cause of slope instability,collapse,rockfall and landslide.The deterioration of structural surface strength under the action of rainfall,resul⁃ting in unstable collapse of slope blocks,can cause geological disasters and pose a serious threat to people’s lives and property.Based on the discrete element numerical analysis method,considering the influence of rainfall on the shear strength of the structural surface,thPe deterioration of the strength parameters of the structural surface and the change law of pore water pressure are analyzed,and the shear strength deterioration model is estab⁃lished.Combined with the principle of coordinate projection,a calculation method of block stability coefficient considering the effect of strength deterioration of structural surface under rainfall is proposed.Based on the finite element analysis method,the influence of rainfall intensity and rainfall duration on the stability of rock slope blocks was studied,and the rela⁃tionship between stability coefficient and rainfall intensity and rainfall duration was further analyzed,then a block stability evaluation method is proposed.The results show that the de⁃terioration of the shear strength of the structural surface under different moisture content is not only affected by the cohesion and internal friction angle,but also related to the pore water pressure.the stability analysis mathematical model considering the rainfall deterioration of the structural surface is constructed for the single⁃slip surface and double⁃slip surface type block.The proposed common evaluation system based on the relationship curve of rainfall duration,rainfall intensity and block stability can provide scientific basis for the stability e⁃valuation of slope block,and promote the prevention and development of slope geological disaster prevention and engineering construction.

关 键 词：降雨作用 含水率 结构面劣化 坐标投影法 数值分析 块体稳定性评价 

分 类 号：TU457[建筑科学—岩土工程]