两种降雨模式下基坑渗流及稳定性研究  

Deep Excavation Seepage Analysis under Two Different Precipitation Modes

作　　者：邱海兵[1] 刘增荣[1] 王海刚[1] 

机构地区：[1]西安建筑科技大学,西安710055

出　　处：《土工基础》2014年第1期64-67,共4页Soil Engineering and Foundation

摘　　要：基于非饱和土渗流及抗剪强度理论,采用瞬时暴雨和连阴雨两种降雨模式,利用MIDAS有限元软件对西安桩锚支护的深基坑边坡进行渗流分析,探讨在不同降雨模式下边坡土体负孔隙水压力消散规律,结果表明,短时间暴雨只会在边坡表层形成一个暂态饱和区,深层土体基质吸力变化不大,而连阴雨会逐渐渗入土体,导致边坡土体饱和;同时,利用得到的孔隙水压力导入边坡稳定分析荷载中,采用强度折减法对边坡进行稳定分析,表明连阴雨对边坡安全系数及支护结构内力的变化影响较大。The seepage analyses in unsaturated soils are performed at a ground anchor supported deep excavation site by using MIDAS GTS finite element software under the different precipitation conditions. In order to simulate the matric suction dissipa- tion in the unsaturated soils, two rainfall modes are considered in the numerical analysis~ transient storm rain and prolonged light rain showers. Under a short period of intensive storm rain, a transient saturated soil zone will be developed underneath the slope surface and the matric suction at deeper soil has little change, whereas, the prolonged light rain showers will gradual ly saturate the entire slope. The pore water pressure developed from the prolonged rain fall is then introduced into the excavated slope model and the stability is analyzed by using the strength reduction method. It is concluded that the prolonged rainfall has larger impact on the stability of the supporting structures and overall stability of deep excavations.

关 键 词：瞬时暴雨 连阴雨 MIDAS 边坡稳定 

分 类 号：TU473[建筑科学—结构工程]