Effect of Sulfate Contaminant on Soil Properties and Infrastructure Safety in Permafrost Regions
Contamination of unfrozen water in frozen soil could have adverse effects on surrounding infrastructure such as foundation instability or deterioration of trafficability.This paper describes the results of the experimental examination of the physical properties and mechanical behavior of Na2SO4 contaminated soil.Initial freezing temperature test,unfrozen water content test and unconfined compression tests were conducted on silts with 3 levels of concentrations (6,18 and 42 ppt) of Na2SO4 and nonsaline cases at temperatures ranging between 0℃ and -20℃.The test results indicate that the presence of salt significantly affect the physical properties and mechanical behavior of the frozen soil.Contamination of soils will cause depression of freezing temperature and degradation of permafrost.The freezing temperature depression ratio of Na2SO4 contaminated soil is 0.028℃/ppt.The unfrozen water content increases with an increase in salinity and temperature.The strength decreases with an increase in salinity,and the strength loss ratio of Na2SO4 contaminated soil is among 0.02-0.04MPa/ppt.Combined the effect of salinity and temperature on the strength,the decrease in strength with increase in unfrozen water content follows an exponential relationship.So estimation of salt concentration in the soil,and predictions of future increases of salt in the soil,is essential for design of buildings and roadways in permafrost.
Contamination Sodium sulphate Freezing temperature Unfrozen water Strength.
Yuan Xizhong Zhu Yuanlin Zhang Ning
Key Laboratory for Special Area Highway Engineering of Ministry of Education,Changan University,Xi State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Key Laboratory for Special Area Highway Engineering of Ministry of Education,Changan University,Xi
国际会议
哈尔滨
英文
1208-1211
2010-07-24（万方平台首次上网日期，不代表论文的发表时间）