摘要
以青藏铁路西格段季节性冻土区路基冻害为背景,通过现场采集典型分布的粉质黏土,考虑温度、水分、盐分、压实度4个因素,进行室内冻胀试验,测试不同温度下路基土体的冻胀率,分析不同含盐量、含水率、压实度和温度下的冻胀试验数据。结果表明:对于不同压实度和含盐量的试样,冻胀率随含水率增加逐渐增大;随着含盐量的增加,土体的起胀温度逐渐降低,土体的冰点也随之降低;含盐量低于1.0%时,随着压实度的增加土体冻胀率呈增大趋势,含盐量为2.0%时,土体冻胀率不随压实度的变化而变化,进一步增大含盐量时,土体的冻胀率随压实度的增加反而降低,说明通过增加土体盐分的方法整治路基冻害是可行的,但要注意用盐量。
Under the background of subgrade frost damage in the seasonally frozen soil area in xige section of Qinghai--Tibet Railway, the typically distributed silt clay on site was collected and an Indoor Frost Heaving Test was conducted considering the four factors of temperature, water, salt and compaction. Through the Indoor Frost Heaving Test, the frost heaving rate of subgrade soil under different temperature conditions was tested and the data of Frost Heaving Test under different salinity, water content, compaction degree and temperature were analyzed. The conclusion is： For samples with different degree of compaction and salinity, frost heaving ratio increases gradually with water content; with the increase of salt content, soil expansion temperature gradually decreased, soil freezing point is reduced; when the salt content is lower than 1%, with the increase of the degree of compaction, the soil frost heave rate increases, when the salt content is 2 % , the rate of frost heave did not change with the degree of compaction, when further increasing the salt content, soil frost heave rate decreased with the increase of compaction degree. It showed that renovating the subgrade frost damage by increasing soil salinity of subgrade is feasible, but the salt dosage should be paid attention to.
作者
巩丽丽
刘德仁
杨楠
王跃武
张延杰
GONG Lili;LIU Deren;YANG Nan;WANG Yuewu;ZHANG Yanjie(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Xining Railway Section of Qinghai--Tibet Railway Company,Xining 810006,China)
出处
《路基工程》
2018年第4期75-79,94,共6页
Subgrade Engineering
基金
青藏铁路公司科技研究开发计划课题(QZ2015-G01)
冻土工程国家重点实验室开放基金(SKLFSE201607)
关键词
铁路路基
冻胀试验
冻胀率
含盐量
含水率
压实度
温度
railway subgrade
frost heaving test
frost heave rate
salt content
moisture content
compaction degree
temperature
