基于Fredlund&Xing参数下不同雨型边坡渗透稳定性分析  

Seepage and Slope Stability Analysis under Different Rainfall Patterns Based on Fredlund&Xing Parameters

作　　者：郁舒阳 张继勋[1] 王军磊[1] 王天兴[1] 朱文炜 胡南雄 

机构地区：[1]河海大学水利水电学院,南京210098

出　　处：《三峡大学学报（自然科学版）》2017年第6期46-51,共6页Journal of China Three Gorges University：Natural Sciences

基　　金：国家科技支撑计划项目(2015BAB07B10)

摘　　要：为研究Fredlund&Xing模型不同非饱和土参数a、m、n在不同雨型下对边坡渗流特性以及稳定性影响,利用Geo-slope软件中的Seep/W和Slope/W模块进行流固耦合计算,分析了总降雨量为0.1m下不同参数在平均型,前锋型,中锋型以及后锋型降雨下对坡顶和坡脚监测点的孔压以及边坡稳定性的变化规律,得出了安全系数的变化曲线,计算结果表明:不同参数下,坡顶处孔压先增大,后逐渐降低,坡脚处孔压先增大,后保持不变;安全系数总体上呈现持续下降的趋势;参数a与进气值相关,a值越小孔压变化越剧烈;参数m与剩余含水量有关,但不同m值之间孔压相差不大;参数n与土-水特征曲线的斜率有关,n越大,孔压变化速率越大,安全系数降幅越大;不同降雨雨型影响了坡顶和坡脚孔压达到最大值的时刻,对安全系数影响较小.研究成果为不同非饱和参数土体在不同降雨雨型下边坡稳定性分析和治理提供了参考.In order to study the influence of different unsaturated soil parameters：a,m,n,which are put for- ward in Fredlund＆Xing model on seepage characteristics and slope stability,the fluid solid coupling is calcu- lated by the Seep/w and Slope/w modules in Geo-slope,and the pore water pressure of top and toe monitoring point as well as slope stability are analyzed under different rainfall patterns such as average type, forward type,center type and post-peak type, the variation curve of safety factor is obtained.Results show that under different rainfall types the pore water pressure increases during the rainfall and then decreases after the rain- fall on the top of slope,while it increases and then maintains unchanged at the toe; the safety factor shows a downward trend on the whole;parameter a is related to air entry value, the smaller a is, the greater pore water pressure changes;parameter m is related to residual water content, the larger m is, the larger pore water pres- sure is,and the lower safety factor is,but the difference of pore water pressure values are little;parameter n is related to the slope of soil-water characteristic curve, the larger n is, the sharper change rate of pore water pressure is, the larger the amplitude reduction of safety factor is;different types of rainfall affect the moment of maximum pore pressure,but have little influence on safety factor.The research results provide a reference for slope stability analysis and treatment of different unsaturated soil parameters under different rainfall patterns.

关 键 词：Fredlund&Xing参数 降雨入渗 降雨雨型 非饱和渗流 边坡稳定 

分 类 号：TU432[建筑科学—岩土工程]