硫酸盐渍土在单向升温时的室内融沉试验研究  

Experimental Study on Indoor Melting and Sinking of Sulphate Saline Soils at Unidirectional Warming

作　　者：张卫兵[1,2] 刘臻祥 任亚军 周鑫磊 李晓 雷过 ZHANG Wei-bing;LIU Zhen-xiang;REN Ya-jun;ZHOU Xin-lei;LI Xiao;LEI Guo(College of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Ministry of Education Engineering Research Center of Efficient Use of Water Resources in Arid Modern Agriculture,Yinchuan 750021,China)

机构地区：[1]宁夏大学土木与水利工程学院,银川750021 [2]旱区现代农业水资源高效利用教育部工程研究中心,银川750021

出　　处：《科学技术与工程》2022年第27期12094-12099,共6页Science Technology and Engineering

基　　金：宁夏自然科学基金(2021AAC03067);宁夏高等学校一流学科建设项目(NXYLXK2021A03);宁夏大学研究生创新项目(GIP2021051)。

摘　　要：硫酸盐渍土的融沉是造成地基二次破坏的主要原因。为了探究不同含盐量和含水率在单向升温条件下硫酸盐渍土的融沉规律,以宁夏地区硫酸盐渍土为研究对象开展室内融沉试验。结果表明:①硫酸盐渍土的融沉可根据环境温度的不同分为三个阶段:升温初期(-24~5℃),融沉率增长较缓;升温中期(5~20℃),融沉率增长速率显著;升温后期(20~24℃),在含盐量较低时融沉率趋于稳定,含盐量较高时增长幅度渐缓。②含水率低于最优含水率时,2%含盐量土体在升温中期融沉率达到最大,而含水率高于最优含水率时,5%含盐量土体在升温后期融沉率达到最大。③含盐量较低(<2%)时,最大融沉率随含盐量增大而增大;含盐量较高(>2%)时,融沉率因含水率的高低呈现两种不同的变化趋势:含水率小于最优含水率的土体最大融沉率开始下降并趋向于稳定,而大于最优含水率的土体最大融沉率继续缓慢增加。④建立的最大融沉率预测模型与试验值有较好的拟合效果,可用于硫酸盐渍土融沉率的预测和评价。The melting and sinking of sulfate saline soils is the main cause of secondary foundation damage. In order to investigate the melting and sinking patterns of sulfate saline soils with different salt and water contents under unidirectional warming conditions, indoor melting and sinking tests were conducted with sulfate saline soils in the central arid region of Ningxia as the research object. The results shows these as follows. Melt and sink of sulfate saline soils can be divided into three stages depending on the ambient temperature: early warming(-24~5 ℃), the melting and sinking rate grows slowly. Mid warming(5~20 ℃), the melting and sinking rate grows at a significant rate. Late warming(20~24 ℃), the melting and sinking rate tends to stabilize at lower salt content and grows slowly at higher salt content. When the moisture content is lower than the optimum moisture content, the 2% salt content soil reaches the maximum melting and sinking rate in the middle of warming, while when the moisture content is higher than the optimum moisture content, the 5% salt content soil reaches the maximum melting and sinking rate in the late warming period. When the salt content is low(<2%), the maximum melting rate increases with the increase of salt content. When the salt content is high(>2%), the soil melting and sinking show two different trends depending on the water content: the maximum melting and sinking rate of soils with water content less than the optimal water content starts to decrease and tends to stabilize, while the maximum melting and sinking rate of soils with water content greater than the optimal water content continues to increase slowly. The established model for predicting the maximum melt and sink rate has a good fit with the experimental values and can be used for the prediction and evaluation of the melt and sink rate of sulfate saline soils.

关 键 词：硫酸盐渍土 单向升温 融沉 砂土 评价 

分 类 号：TU448[建筑科学—岩土工程]