摘要
为分析各种工况下的滑坡稳定性演化规律,以贵州省思南县官寨滑坡的稳定性分析为例,首先通过泊松分布法计算出研究区每发生一次连续5 d降雨的雨型及其累积降雨量的概率,再结合饱和-非饱和渗流理论和非线性有限元分析法,探究雨型以及累积雨量对滑坡渗流场和稳定系数变化率的影响。结果表明:连续5 d降雨包含的4种雨型中,先升后降型发生概率最大,先降后升型发生概率最小;连续5 d累积降雨发生概率随降雨量的增大逐步递减。当累积降雨量一定时,滑坡浸润线变化趋势与各自对应雨型的降雨规律基本保持一致。边坡稳定性系数值在持续性降雨作用下逐步降低,其中累积降雨量一定时,下降型降雨作用下滑坡稳定性系数在前4 d下降最多,上升降雨作用下滑坡稳定性系数下降最少。另外,上升型降雨作用下滑坡稳定性变化率逐渐上升,下降型降雨作用下稳定性变化率在逐渐下降,两种雨型作用下的稳定性变化率介于两者之间。
It is of great significance to study the evolution law of landslide stability under various working conditions.Guanzhai landslide in Sinan County of Guizhou province was selected as case study.Firstly,the Poisson distribution method was used to calculate the probabilities of each continuous five-day rainfall and its corresponding rainfall type.Then the saturated-unsaturated seepage theory and the nonlinear finite element analysis were combined to explore the effects of cumulative five-day rainfall and rainfall type on the landslide seepage and change rate of stability coefficient.The results show that the first rising and then falling rainfall typeis of maximum occurrence probability among the four continuous five-day rainfall while the first falling and then rising type is of minimum occurrence probability.The probability of rainfall decreases along with the increase of cumulative rainfall.When cumulative rainfall is constant,the change raw of landslide seepage line is consistent with the rainfall raw of corresponding rainfall type.The landslide stability coefficient decreases along with the rain continues.When the cumulative rainfall is constant,the landslide stability coefficient decreases most in the former four days under the effect of falling-type rainfall while the landslide stability decreases least under the effect of rising-type rainfall.In addition,the change rate of landslide stability coefficient gradually rises under rising-type rainfall while the change rate of landslide stability decreases under the falling-type rainfall,with the other two rainfall types falling somewhere in between.
作者
胡涛
樊鑫
王硕
HU Tao;FAN Xin;WANG Shuo(Faculty of Engineering,China University of Geosciences,Wuhan 430074,China;Geological Engineering Exploration Institute of Guizhou Province,Guiyang 550002,China;Emergency Management Agency of Tongren City,Tongren 554300,China)
出处
《科学技术与工程》
北大核心
2020年第14期5521-5529,共9页
Science Technology and Engineering
基金
国家自然科学基金(41572292)。
关键词
滑坡稳定性
累积降雨量
雨型
浸润线
稳定性变化率
landslide stability coefficient
cumulative rainfall
rainfall type
landslide seepage line
change rateof stability coefficient
