高温-高含冰量冻土压缩变形特性研究  

STUDY ON COMPRESSION DEFORMATION OF WARM AND ICE-ENRICHED FROZEN SOIL

作　　者：郑波[1,2,3] 张建明[1] 马小杰[4] 张军伟[2,3] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000 [2]中国铁道科学研究院,北京100081 [3]中铁西南科学研究院有限公司,四川成都610031 [4]浙江建设职业技术学院,浙江杭州311231

出　　处：《岩石力学与工程学报》2009年第A01期3063-3069,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：中国科学院寒区旱区环境与工程研究所知识创新工程项目(2004104);中国科学院知识创新工程重要方向性项目(KZCX3-SW-351);中国科学院知识创新工程重大项目(KZCX1-SW-04)

摘　　要：高温–高含冰量冻土在外荷载作用下会产生较大的压缩变形,对路基稳定性产生极大影响。室内高温–高含冰量冻土恒载变温压缩试验表明:在较低温度-1.5℃,-1.0℃下,冻土的压缩量相对较小,而在较高温度-0.5℃,-0.3℃下,冻土的压缩量相对较大,且在-0.5℃、-0.3℃两级温度荷载下的压缩量占总压缩量的70%以上;温度是影响高温–高含冰量冻土压缩系数的主要因素,在高温区内,压缩系数随温度的升高显著增大,当温度为-1.5℃时,冻土压缩系数为0.04MPa-1,而当温度升高到-0.3℃时,冻土压缩系数变为0.29MPa-1。路基沉降变形计算表明:对于砂砾路面路基,当路堤高度大于临界高度时,在未来50a内不会发生融沉变形,路基的最大沉降量约为20cm,变形符合铁路稳定性要求;当路堤高度小于临界高度时,路基下冻土随着时间的延长会发生融化,产生融沉变形,导致路基变形急剧增大,造成路基失稳。The warm and ice-rich frozen soil under an outside load will generate relatively large compression deformation which greatly influences the stability of roadbed. The compression tests of warm and ice-rich frozen soil show that under the constant load and variable temperatures, the compressibility at - 1.5 ℃ or - 1.0 ℃ is smaller than that at -0.5 ℃ or -0.3℃, and the latter accounts for 70% of the total compressibility. Temperature is the key factor to compressibility coefficient of the warm and ice-rich frozen soil. The compressibility coefficient greatly increases with increasing of temperature. When temperature is at -1.5 ℃ and -0.3 ℃, the compressibility coefficient is 0.04 MPa^-1 and 0.29 MPa^-1, respectively. The numerical calculation of embankment deformation shows that, the maximum value of the embankment settlement deformation is about 20 cm in the coming 50 a when the height of embankment is bigger than the critical height of embankment. The maximum value of 20 cm is certainly acceptable. However, once the height of embankment is less than the critical height of embankment, the thawing settlement deformation of embankment will happen. So the embankment will be steady as long as the heat stability of embankment can meet the design requirement.

关 键 词：土力学 青藏铁路 高温-高含冰量冻土 压缩系数 路基沉降变形 路基稳定性 

分 类 号：TU43[建筑科学—岩土工程]