降雨条件下裂隙土坡水土响应与变形破坏特征试验研究  

Hydrological response and deformation and failure characteristics of tension fracture slope under rainfall conditions

作　　者：王司法 江兴元 杨义 孙乾征 孟生勇 WANG Sifa;JIANG Xingyuan;YANG Yi;SUN Qianzheng;MENG Shengyong(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,Guizhou,China;Key Laboratory of Karst Geological Resources and Environment of Ministry of Education,Guizhou University,Guiyang 550025,Guizhou,China;104 Geological Brigade,Bureau of Geology and Mineral Exploration and Development Guizhou Province,Duyun 558000,Guizhou,China;Wengfu(Group)Co.,Ltd.,Guiyang 550508,Guizhou,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025 [3]贵州省地质矿产勘查开发局一〇四地质大队,贵州都匀558000 [4]瓮福(集团)有限责任公司,贵州贵阳550508

出　　处：《水利水电技术(中英文)》2024年第11期143-153,共11页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(42007271);贵州省科技支撑计划项目(黔科合支撑[2023]一般119)。

摘　　要：【目的】为了探究裂隙对斜坡降雨入渗过程的影响,研究在降雨过程中裂隙斜坡变形破坏过程,以及斜坡破坏过程中的体积含水率、孔隙水压力和土压力的响应过程与湿润锋的演化规律,【方法】采用物理模型试验与数值模拟结合的方法研究含裂隙斜坡的降雨入渗水土响应和变形破坏过程,在物理模型试验过程中实时监测风险斜坡的含水率、孔隙水压力、土压力、坡体位移及变形。在数值模拟中加入降雨对有效饱和度与塑性应变进行监测,并增加无裂隙斜坡工况,对比裂隙对斜坡入渗破坏的影响。【结果】结果显示,裂隙作为降雨入渗的优势通道,使得在降雨条件下斜坡渗流场发生改变,降雨前期湿润峰呈现漏斗状,在坡表出现裂隙过程中孔隙水压力传感器会发生波动,坡体大规模破坏前坡体内部土压力会出现分布改变情况;裂隙成为坡体的天然滑面,坡体最终沿裂隙滑动。【结论】降雨过程中滑坡变形破坏分为三个阶段,微裂隙发展、局部破坏和大面积破坏阶段,表现为前期张拉牵引—中期坡表坍塌—后期推移破坏的滑动模式。坡体前部位移有四个阶段,即,无位移阶段、缓慢蠕动阶段、快速变形阶段、缓慢蠕动与短距离快速变形阶段。与无裂隙斜坡相比,含裂隙斜坡的降雨入渗速度较快,相同降雨时长下,无裂隙塑性变形区仅限于坡脚部位。由于整个坡体为非均匀入渗,造成坡肩下部入渗缓慢,使得该部位成为后部坡体滑动的阻力区,降雨前期有效阻止了坡体沿裂隙的滑动。在坡体前部发生滑动后,前部抗滑力减小,坡体后部由于持续降雨增重与裂隙持水作用,下滑力增大,最终坡体滑面沿裂隙延伸。[Objective]In order to explore the influence of fractures on the rainfall infiltration process of slope,the response of volume water content,pore water pressure and earth pressure in the deformation and failure process of fractured slope during rainfall and the evolution law of wetting front were studied.[Methods]In this paper,a combination of physical model test and numerical simulation is used to study the response of rainfall infiltration and the deformation and failure process of fractured slope.The moisture content,pore water pressure,soil pressure,slope displacement and deformation of risk slopes were monitored in real time during the physical model test.Rainfall was added to the numerical simulation to monitor the effective saturation and plastic strain,and increase the working condition of non fractured slopes to compare the impact of fractures on slope infiltration failure.[Results]As the dominant channel of rainfall infiltration,cracks change the seepage field of slope under rainfall conditions,and the wet peak in the pre-rainfall period is funnel-shaped.The pore water pressure sensor will fluctuate in the process of slope surface cracks,and the distribution of soil pressure inside the slope will change before large-scale slope failure.The cracks become the natural sliding surface of the slope,and the slope eventually slides along the cracks.[Conclusion]The landslide deformation failure in the rainfall process can be divided into three stages:microfracture development,local failure and large area failure.It is manifested as the sliding mode of early tensioning traction,mid-stage slope collapse and late push failure.There are four stages of slope front displacement:no displacement stage,slow creep stage,fast deformation stage,slow creep stage and short distance fast deformation stage.Compared with slopes without cracks,slopes with cracks have a faster rainfall infiltration rate.Under the same rainfall duration,the plastic deformation zone without cracks is only limited to the foot of the slope.The whole

关 键 词：裂隙 降雨入渗 斜坡变形破坏 数值模拟 模型试验 

分 类 号：P642.22[天文地球—工程地质学] TU411.93[天文地球—地质矿产勘探]