大气作用下膨胀土边坡的现场响应试验研究  

Field response tests on expansive soil slopes under atmosphere

作　　者：孔令伟[1] 陈建斌[1] 郭爱国[1] 赵艳林[2] 吕海波[2] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学重点实验室,湖北武汉430071 [2]广西大学土木建筑工程学院防灾减灾研究所

出　　处：《岩土工程学报》2007年第7期1065-1073,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家重大基础研究前期研究专项(2003CCA02200);交通部西部交通建设科技项目(200631878530);中国科学院武汉岩土力学研究所领域前沿基金项目(Q110301)

摘　　要：在广西南宁地区建立了缓坡、陡坡与坡面种草3种类型膨胀土边坡的原位监测系统。采用小型气象站、土壤含水率TDR系统、烘干法、温度传感器、测斜管和沉降板跟踪测试了边坡含水率、温度、变形等随气候变化的演化规律。认为降雨是膨胀土边坡发生灾变的最直接的外在因素,蒸发效应是边坡灾变的重要前提条件,而风速、净辐射量、气温和相对湿度是间接影响因素;土温变化可间接反映边坡不同位置的含水率变化性状;边坡变形主要集中在表层土体,坡中变形最大,其次是坡顶,坡脚处变形最小,陡坡在大气作用下发生了渐进性破坏;草皮覆盖有利于保持边坡表层土体水分、降低坡面冲刷和径流量、抑制边坡变形,且对土温有很好的削峰填谷作用。A field monitoring system for gentle slopes, steep slopes and gentle slopes with grass coverage was established in expansive soil of Nanning, Guangxi, and the development of the deformation, water content and temperature for expansive soil slopes with the local atmosphere was measured by the six-parameter mini-environmental station, TDR system, oven-drying method, temperature sensors, inclinometer and settlement plates. The rainfall was considered as the most direct external factor of slope disasters and the evaporation effect was one of the important premises, while the wind velocity, net solar radiation, air temperature and relative humidity were indirect factors. The variation of soil temperature could reflect the behaviors of water content in different positions of slopes. The slope deformations were mainly concentrated in the surficial soil, and the position of the maximum deformation of slopes was in the middle part. The progressive failure occurred in the steep slopes. Grass coverage could not only maintain the water content of slope surface and reduce the erosion of precipitation, runoff and deformation, but also play a role of peak clipping and valley filling for soil temperature.

关 键 词：膨胀土边坡 大气 现场响应试验 气象站 蒸发量 

分 类 号：TU443[建筑科学—岩土工程]