膨胀土堑坡变形的湿热耦合效应及其与降雨历时的关系  

Moisture-heat Coupling Effect of Expansive Soil Cut Slope Deformation and Relationship between Deformation and Raining Time

作　　者：李雄威[1,2] 孔令伟[1] 郭爱国[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]常州工学院土木建筑工程学院,江苏常州213002

出　　处：《公路交通科技》2009年第7期1-6,共6页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金资助项目(10872210);中国科学院知识创新工程重要方向资助项目(kzcx2yw150);交通部西部交通建设科技资助项目(200631878530)

摘　　要：在广西南宁地区建立了不同开挖坡度的膨胀土边坡,通过现场试验论证出堑坡变形与降雨历时的关系,并分析其湿热耦合效应。历时两个雨季和一个旱季的试验结果表明,坡面水平变形与降雨持续时间具有较好的相关性,只有在一定雨强下持续的降雨过程才能使边坡产生较大的变形;土体含水量变化是影响边坡变形的主要因素,而温度变化是促进因素,二者的耦合作用使得膨胀土边坡趋向不稳定;在考虑膨胀土边坡的渗透特性后,建立了堑坡变形与降雨历时的关系,表达式可用于预测边坡总变形量,也可换算成变形速率对陡坡的变形突变进行预警,具有较强的工程适用性。同时,监测结果也表明,在采用植被防护后膨胀土边坡的变形迅速减小,说明植被护坡是一种有效的堑坡防护方式。Expansive soil cut slopes of deferent gradients were built up in Nanning, Guangxi, the relationship between deformation and the raining time was discussed, and the moisture-heat coupling effect of deformation was analyzed through the field test. The test result during one dry season and two rainy seasons in the monitoring period shows that （1） the correlation between horizontal deformation and raining time is well and only successive raining in certain intensity can induce large deformation; （2） the water content variety is the key factor to the slope deformation and the temperature variety may accelerate the deformation process, the coupling action makes the slope unstable. The relationship expression of deformation and the mining time was established on the basis of slope permeability analysis which is suitable to predict total deformation of the slope and converse deformation rate to warn the sudden change of deformation earlier. At the same time, the monitoring results show that the slope deformation decreases immediately with vegetation protected which illustrates that vegetation is an effective protection method for cut slope.

关 键 词：道路工程 变形 现场试验 膨胀土路堑边坡 湿热耦合 

分 类 号：U416.167[交通运输工程—道路与铁道工程]