摘要
以青藏粘土的重塑饱和土样为研究对象,使土样在封闭系统下经历一个冻融循环,通过试验考察土的工程性质在冻融作用下的变化规律.试验表明:冻融循环对不同初始密度的土具有双重作用,使低密度的土变得密实,而高密度的土密度降低.密度变化的同时,其力学性质也发生相应的变化.试验分析了在相同冻结条件下,随着初始密度变化冻融后力学参数的变化规律.
It is well known that freeze-thaw can lead to changes in engineering properties of soils. This will impact the cold regions engineering for certain. In this paper, a frost-susceptible soil, a typical silty clay obtained along the Qinghai-Tibet railway is taken as the study object. The clay samples are experienced one freeze-thaw cycle in a closed system （i. e. no water supply）. The samples are tested with a wide range of density and under the same freezing condition. Direct shear and 1-D compression tests are carried out on the samples before and after freeze-thaw. Testing results before and after freeze-thaw is then comparatively analyzed. It is found that freeze-thaw can densify the soils with smaller original densities, while make the dense soils looser. Changes in mechanical properties, such as, strength parameters, pre-consolidation pressure and modulus are changed at the same time. With the increase of the dry unit weight, all the pre-consolidation pressure, modulus and cohesion increase at first and then decrease. There is a critical dry unit weight, at this point all of them do not change after freeze-thaw. The change of pre-consolidation pressure, modulus and cohesion are correlated with the change of dry unit weight after freeze-thaw cycle. As for the friction angle, it always increased after freeze-thaw.
出处
《冰川冻土》
CSCD
北大核心
2008年第1期165-169,共5页
Journal of Glaciology and Geocryology
基金
中国科学院百人计划项目(2006年)资助
关键词
冻融
强度参数
前期固结压力
一维压缩
freeze-thaw
strength parameters
pre-consolidation pressure
1-D compression
