降雨入渗对粗粒土路堤变形与稳定性的影响  

Effect of rainfall infiltration on additional settlement and stability debasement of granular soil fillings embankment

作　　者：陈晓斌[1,2] 徐望国[1] 刘小平[3] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075 [2]广州市建筑科学研究院,广东广州510440 [3]湖南大学土木工程学院,湖南长沙410082

出　　处：《中南大学学报（自然科学版）》2011年第3期765-771,共7页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50908233);中国博士后科学基金资助项目(20080440996)

摘　　要：针对土石混填粗粒土路堤,分析其降雨入渗机理,得到固定颗粒粒径时的总吸力随饱和度衰减规律,对比降雨入渗深度计算公式。根据饱和土强度折减规律,采用强度折减简要模拟降雨入渗效果,并结合工程实践建立数值模型,对降雨入渗作用下粗粒土路堤变形及稳定性进行计算分析。工程实例计算结果表明:降雨入渗对路堤变形影响明显,随着入渗深度增加,路堤附加沉降增大,当单次入渗深度为2 m时,附加沉降可达1.30 cm;降雨入渗对粗粒土路堤稳定性也有明显影响,入渗作用扩大路堤塑性区范围,降低路堤稳定性。The rainfall infiltration mechanism analysis for the granular soil embankment was executed,and the metric suction and shearing strength was generalized when the grain diameter were fixed.The law for granular soil＇s metric suction and shearing strength attenuation was obtained and the rainfall infiltration depth calculation formulas were discussed.According to unsaturated soil＇s strength attenuation law,the strength discount method was used for the rainfall infiltration effects simulation,and the embankment additional settlement and stability debasement resulting from rainfall infiltration was stimulated by the embankment numerical computation model.The computation results show that rainfall infiltration has effect on the embankment additional settlement,and the additional settlement increases with the increase of the infiltration depth incensement.While the first time infiltration depth reaches 2 m,the additional settlement can reach 1.30 cm.The embankment stability is obviously affected by rainfall infiltration,which expands the plastic zones in the embankment numerical model and thus reduces the stability coefficient.

关 键 词：降雨入渗 入渗深度 附加变形 路堤稳定性 粗粒土 

分 类 号：TU471.8[建筑科学—结构工程]