摘要
为研究库水位骤降联合间歇性降雨对库岸古滑坡渗流稳定的影响,基于非饱和渗流原理,考虑不同速率库水位骤降、不同类型间歇性降雨及降雨发生时刻,利用Geo-Studio软件对滑坡在库水位骤降遭遇间歇性降雨时的渗流特性、位移变形及稳定性进行了有限元模拟。结果表明:静库水位下孔压呈间歇式升降,中部孔压最大且发生时刻最迟,此时表层位移最大,易发生浅层滑坡;库水位骤降速率和孔压消散的快慢呈正相关,中上部具有表层滑坡风险,下部埋深20~25 m处具有深层滑坡趋势;降雨发生时刻越早,孔压达到峰值越快,库水位骤降初期遭遇间歇性降雨主要影响滑坡上部位移变形,而骤降后期发生间歇性降雨对滑坡中下部位移变形影响显著。各降雨类型的最小稳定性系数大小为翼锋型>升阶型>中锋型>降阶型,而与库水位组合的滑坡安全稳定影响程度为库水位下降联合间歇性降雨>静库水位下间歇性降雨>单纯库水位骤降。
In order to study the influence of reservoir water level sag combined with intermittent rainfall on the seepage stability of reservoir bank ancient landslide,based on the unsaturated seepage principle,considering different rates of reservoir water level sag,different types of intermittent rainfall and rainfall occurrence time,Geo-studio software is used to carry out finite element simulation on the seepage characteristics,displacement,deformation and stability of the landslide when the reservoir water level plummets and meets intermittent rainfall.The results show that the pore pressure rises and falls intermittently under the static reservoir water level.The pore pressure in the middle reaches the maximum and occurs at the latest.At this time,the surface displacement is maximum and shallow landslide is easy to occur.There is a positive correlation between the plunge rate of reservoir water level and the dissipation rate of pore pressure.There is a surface landslide risk in the middle and upper part of the reservoir,and a deep landslide trend in the lower part of the reservoir buried 20~25 m.The earlier the rainfall occurs,the faster the pore pressure reaches the peak.The intermittent rainfall in the early stage of reservoir water level plummeting mainly affects the displacement deformation of the upper part of the landslide,while the intermittent rainfall in the late stage of plummeting has a significant impact on the displacement deformation of the middle and lower part of the landslide.The minimum safety factor of each rainfall type is in the order of wing type > ascending type > center type > descending type,and the influence degree of landslide safety and stability combined with reservoir water level is in the order of intermittent rainfall coupled with reservoir water level descending > intermittent rainfall coupled with static reservoir water level > simple reservoir water level plummeting.
作者
谷建永
田斌
GU Jian-yong;TIAN Bin(School of Water Resources and Environment,Three Gorges University,Yichang 443002,Hubei Province,China)
出处
《中国农村水利水电》
北大核心
2022年第9期188-194,共7页
China Rural Water and Hydropower
基金
国家重点研发计划项目(2017YFC1501100)。
关键词
库水位
间歇性降雨
非饱和渗流
变形
稳定性
reservoir water level
intermittent rainfall
unsaturated seepage
deformation
stability
