摘要
目前,关于库水位联合降雨不同工况组合下滑坡渗流稳定问题的研究较少,为此基于非饱和渗流及稳定分析理论,以三峡库区蔡坡堆积体为研究背景,利用Geostudio软件对降雨、库水位及其组合工况下的堆积体边坡的渗流特性及稳定性进行了数值模拟,得到了边坡不同部位的孔压变化、边坡的安全系数曲线及湿润锋发展规律。结果表明:库水位骤降速率越大,则孔压下降越快,降雨强度越大,则孔压上升幅度越大,单纯降雨孔压上升幅度要大于库水位骤降情况孔压下降幅度。降雨发生在库水位骤降不同时刻的孔压特性综合了单纯降雨与单纯库水位下降的综合特性,位于边坡下部的孔压值要大于上部。库水位骤降下安全系数先降后升,降雨情况下安全系数先下降后保持稳定,单纯降雨导致的安全系数降幅要大于单纯库水位骤降情况,降雨发生在库水位骤降不同时刻下,安全系数在降雨时刻有一个突降,其中降雨发生在第6~8 d安全系数最小。降雨联合库水位骤降边坡失稳概率最大。库水位骤降速率越大浸润线越下凸,降雨强度越大边坡表层的湿润锋发展越充分,降雨与库水位联合作用下湿润锋变化规律相似,但是浸润线的下凸程度不同,这是导致这种情况下边坡安全系数不一致的原因。
At present,little attention has been paid to the seepage and stability of landslide under different combination of reservoir water level and rainfall.Based on the theory of unsaturated seepage and stability analysis,taking the Caipo accumulation body in the three Gorges Reservoir area as the research objective,the rainfall was analyzed by the Geostudio software.The seepage characteristics and stability of the accumulated slope under the reservoir water level and its combined working conditions were simulated by numerical simulation,and the variation of pore pressure in different parts of the slope,the safety factor curve of the slope and the development law of the wetting front were obtained.The results showed that the larger the drop rate of reservoir water level,the faster the pore pressure decrease,the greater the intensity of rainfall does,the larger the range of pore pressure rise,and the greater the amplitude of pore pressure rise of simple rainfall is greater than that of reservoir water level.The variation characteristics of pore pressure at the time of sudden drop of reservoir water level are combined with rainfall and reservoir water level.The safety coefficient of reservoir water level drops first and then rises.In case of rainfall,the safety coefficient drops first and then remains stable.The amplitude of safety coefficient caused by rainfall is larger than that of reservoir water level drop.Rainfall occurs at different times of reservoir water level.The safety coefficient has a sudden drop at the time of rainfall and arrives at minimum,of which rainfall occurs at the 6 th-8 th day.The probability of slope instability is the highest when the water level suddenly drops in the combined rainfall reservoir.The water level of reservoir drops more rapidly.The greater the degree of degree,the fuller the progress of the wet front on the surface of the slope.The change law of the wetted front under the action of rainfall and reservoir water level is similar,but the degree of convex of the infiltration line is different,which is the reason for the inconsistent safety factor of the slope in this case.
作者
李险峰
LI Xianfeng(Department of Architectural Engineering,Huaibei Vocational and Technical College,Huaibei 235000,China)
出处
《水资源与水工程学报》
CSCD
2019年第6期194-200,共7页
Journal of Water Resources and Water Engineering
基金
安徽省质量工程项目“工程造价教学团队”(2016jxtd108)
关键词
库水位变动
降雨
渗流特性
边坡稳定
数值模拟
蔡坡堆积体
三峡库区
reservoir water level variation
precipitation
seepage characteristics
slope stability
numerical simulation
Caipo accumulation body
Three Gorges reservoir area