不同降雨类型与库水位波动耦合作用下的土质滑坡稳定性分析  

Landslide instability induced by sudden lower in water level combined with different rainfall types

作　　者：王乐 秦世伟[1] WANG Le;QIN Shiwei(Department of Civil Engineering Shanghai University ,Shanghai 200444,China)

机构地区：[1]上海大学土木工程系,上海200444

出　　处：《中国地质灾害与防治学报》2018年第6期103-111,共9页The Chinese Journal of Geological Hazard and Control

摘　　要：为研究不同类型降雨(平均型,前峰型,中峰型以及后峰型)联合库水位骤降情况下的滑坡失稳模式,根据非饱和渗流原理,利用加拿大著名岩土软件Geo-slope2012,针对某自拟滑坡体在库水位骤降联合降雨工况下进行了渗流特性以及稳定性分析,计算结果表明:库水位下降过程中滑坡体内部孔压存在一个"延迟"效应,监测点距离库岸越远,"延迟"效应越明显;库水位下降速率越大,最小稳定系数出现的时刻越早,最小稳定系数越小;不同降雨类型影响了孔压达到峰值的时间以及最小稳定系数的出现时间;不同降雨类型下最小稳定系数大小为前峰型>中峰型=平均型>后峰型;降雨发生在库水位下降不同时刻时影响了监测点孔压的瞬时变化;不同工况下滑坡失稳模式均为下部浅层滑坡首先失稳,然后深层滑坡失稳,而上部浅层滑坡较为稳定,不容易发生失稳。研究成果为认识不同降雨类型联合库水位骤降下滑坡失稳模式提供了参考。In order to study the landslide failure model induced by different types of rainfall (average type, front type,center front type and post peak type)combined with sudden drop of reservoir water level,based on the unsaturated seepage principle,Geo-slope2012 Software was adopted to analyze the seepage characteristics and stability of a self-designed landslide under sudden drop of reservoir water level combined with rainfall,the results show that:the pore pressure in landslide body during the process of reservoir water level falling appears a "delay"effect,this effect becomes more obvious while the monitoring point getting away from the bank.The greater the water level drop rate is,the earlier the minimum stability coefficient appears and the smaller the minimum stability coefficient is.Different rainfall types affect the appearance time of pore pressure and the minimum stability coefficient.The minimum stability coefficient under front type rainfall is bigger than that of the center front type,which is equals to the average type,and the minimum stability coefficient under post peak type rainfall is the smallest.The instantaneous change of pore pressure at monitoring point is affected by rainfall at different time when the water level of reservoir drops.The mode of landslide instability under different calculation conditions is that the lower shallow landslide first loses stability,and then the deep layerlandslide loses stability,while the upper shallow landslide is more stable,so it is hard to of the study provide a reference for understanding the landslide instability model under water level e combined with different rainfall types. failure.The resuhs the sudden drop of water level e combined with different rainfall types.

关 键 词：不同类型降雨 库水位骤降 非饱和渗流 Geo—slope 滑坡失稳模式 

分 类 号：TU432[建筑科学—岩土工程]