青藏铁路路基下高温-高含冰量冻土旁压试验研究  

Study on warm and ice-rich permafrost beneath Qinghai-Tibet Railway embankment with pressiometer

作　　者：马小杰[1] 张建明[1] 郑波[1] 李双洋[1] 

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试验室

出　　处：《岩土力学》2008年第3期764-768,共5页Rock and Soil Mechanics

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(No.2004104);中国科学院知识创新工程重要方向项目(No.KZCX3-SW-351);中国科学院知识创新工程重大项目(No.KZCX1-SW-04);中国科学院国际合作重点项目(No.GJHZ0529)联合资助

摘　　要：为研究青藏铁路路基下高温-高含冰量冻土的力学性质,在青藏铁路北麓河试验段开展一系列旁压强度试验。试验研究表明:路基的增加引起路基下多年冻土温度升高,未冻水含量增加,最终导致冻土旁压临塑压力Pf下降31%,旁压极限压力Pl下降44%,旁压剪切模量Gm下降80%。对于高温冻结黏土,富冰冻土和饱冰冻土Gm对温度变化的敏感性高于含土冰层;饱冰冻土的Pf和Pl对温度变化的敏感性高于富冰冻土和含土冰层。In order to study the mechanics characters of the warm and ice-rich permafrost beneath the embankment of Qinghai-Tibet Railway, a series of pressiometer tests were conducted in the Beiluhe test site of Qinghai-Tibet Railway. The tests results indicate that the temperature of the permafrost beneath the embankment gets higher; unfrozen water of the permafrost increases; the critical plastic load Pfdescends 31%; the ultimate load P1 descends 44 % and the shear modulus Gm descends 80 % because of the embankment. For warm permafrost, the sensitivities of shear modulus Gm to the temperature of both ice-saturated and ice-rich permafrost are higher than that of ice with soil inclusions; the sensitivities of the critical plastic load Pf and the ultimate load PI to the temperature of ice-saturated permafrost are higher than that of ice-rich permafrost and ice layer with soil inclusions.

关 键 词：旁压仪 高温-高含冰量冻土 青藏铁路 路基 

分 类 号：TU413.4[建筑科学—岩土工程]