土体单向冻结对土中水分迁移的影响  

Effects of unilateralist freezing on the moisture migration of soil

作　　者：张婷[1] 杨平[1] 

机构地区：[1]南京林业大学土木工程学院,江苏南京210037

出　　处：《南京林业大学学报（自然科学版）》2013年第1期117-121,共5页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：苏州市科技局苏州轨道交通专项课题(ZXJ0802);南京地下铁道有限公司科研项目(2011)

摘　　要：以江苏南京、苏州、无锡等地区典型的浅表土为研究对象,对非饱和土进行了单向冻结试验,研究了不同含水率、干密度以及冻结时间对土中水分迁移特性的影响。结果表明:试样冻结锋面的位置与冻结时间有关,冻结2 h后的发展速度(1.20 cm/h)略小于前2 h的发展速度(1.55 cm/h);土中水分迁移量及迁移范围与干密度成反比,试样顶端含水率减小值及底端含水率增加值与干密度大小有关;处于非饱和状态的淤泥质黏土初始含水率越大,经单向冻结后造成的水分迁移效果越明显;粉砂中易形成快速冻结,初始含水率对水分迁移能力影响不大;相同冻结条件下淤泥质粉质黏土冻结后各冻土段含水率增量基本相同。The test object was column sample of shallow top soil in Nanjing,Suzhou and Wuxi,the unsaturated soil was tested by unilateralist freezing way tests on unsaturated soil,the soil＇s moisture migration behaviors were analyzed under the influence of moisture content,dry density and freezing time.The following conclusions could be drawn：the sample＇s freezing front position was relationship with freezing time,the freeze frontal movement speed of begin two hours（1.55 cm/h） was slightly higher than the end of the two hours（1.20 cm/h）.The moisture migration capacity and scope were negative correlation with the soil＇s dry density,the top and bottom moisture variation of sample was relationship with dry density.After unilateralist freezing,the moisture migration was remarkable in unsaturated muddy clay when soil＇s moisture content was higher.The results also showed that mealy sand was apt to quickly freeze,and moisture migration capacity of that was little impacted by initial moisture content of soil.The water content increment was the same in each frozen section of silty clay under the same freezing conditions.

关 键 词：土质 单向冻结 水分迁移 含水率 干密度 

分 类 号：TU445[建筑科学—岩土工程]