| 硫酸盐渍土含水率单次递减条件下的盐胀特性 |
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| 引用本文： | 曹亚鹏,文桃,米海珍,周凤玺,杨鹏.硫酸盐渍土含水率单次递减条件下的盐胀特性[J].岩土力学,2018,39(3):881-888. |
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| 作者姓名： | 曹亚鹏 文桃 米海珍 周凤玺 杨鹏 |
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| 作者单位： | 1. 兰州理工大学 土木工程学院，甘肃 兰州 730050；2. 长江师范学院 土木建筑工程学院，重庆 408100 |
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| 基金项目： | 国家自然科学基金资助项目（No.51568043）；重庆市教委科学技术研究项目（No.KJ1601217）。 |
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| 摘 要： | 为探究硫酸盐渍土在含水率递减下的盐胀特性，通过自主设计的试验装置，在室内开展了11组含水率单次递减下的盐胀试验，共历时2 868 h。结果表明：在含水率单次递减下硫酸盐渍土的起胀含盐量约为1.2%。含盐量<1.2%时，土体干缩，干缩量与含盐量近似呈下凸的二次抛物线规律，且干缩峰值含盐量约为0.5%；含盐量≥1.2%时，土体膨胀，且盐胀率与含盐量近似呈线性增大规律。盐胀敏感含水率区间受含盐量影响很小，含盐量从1.5%增至4.0%，盐胀敏感含水率区间基本稳定。此外，含水率递减速率与含盐量呈负相关规律，同一含盐量的硫酸盐渍土，其含水率的递减速率随含水率的降低亦减慢。基于以上试验结果，进一步开展了4组单次降温下的盐胀对比试验，结果表明：含盐量升高时，起胀温度区间逐渐升高，盐胀敏感温度区间的区间范围逐渐扩大。单次降温下的盐胀率均高于含水率单次递减下的盐胀率，且随着含盐量的升高两试验条件下的盐胀率差值趋于一常数。研究结果对西北地区高含盐量的残余型硫酸盐渍土地基的盐胀性评价具有重要指导意义。
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| 关 键 词： | 硫酸盐渍土 盐胀 干缩 含水率 单次递减 单次降温 |
| 收稿时间： | 2016-12-10 |
Salt expansion properties of sulfate saline soils under one time decrease of water content |
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| CAO Ya-peng,WEN Tao,MI Hai-zhen,ZHOU Feng-xi,YANG Peng.Salt expansion properties of sulfate saline soils under one time decrease of water content[J].Rock and Soil Mechanics,2018,39(3):881-888. |
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| Authors: | CAO Ya-peng WEN Tao MI Hai-zhen ZHOU Feng-xi YANG Peng |
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| Institution: | 1. College of Civil Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. School of Civil and Architectural Engineering, Yangtze Normal University, Chongqing 408100, China |
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| Abstract: | In order to explore salt expansion properties of sulfate saline soils under the decrease of water content, 11 sets of indoor simulation tests under one time decrease of water content, lasting for 2 868 hours, have been carried out using the self-developed experimental equipment. It is shown that the salt content of swelling initiation of sulfate saline soil is 1.2%. The volume of sulfate saline soil shrinks when the salt content of sulfate saline soil is less than 1.2%, and there is an approximate second-degree lower convex parabola correlation between salt expansion rate and salt content. The drying shrinkage rate of sulfate saline soil reaches the maximum value when the salt content is 0.5%. When the salt content is greater than or equal to 1.2%, the volume of sulfate saline soil swells. The salt expansion rate increases with the increase in salt content and there is a linear correlation between the two. The sensitive water content range of salt expansion, slightly influenced by salt content, is generally stable when salt content increases from 1.5% to 4.0%. It can also be concluded that the decrease rate of water content is negatively correlated with the salt content, and the decrease rate of water content in the same salt content decreases with the decrease of water content. Based on the above test results, 4 sets of salt expansion tests have been carried out under single cooling. It is shown that the temperature range initiating swelling of sulfate saline soil gradually goes up and the interval range of salt sensitive temperature range gradually expands with the increase in salt content. According to the test results from two kinds of test conditions, the salt expansion rate of single cooling is higher than the salt expansion rate of one time decrease of water content. However, the difference between the salt expansion rate of the two testing conditions is basically constant with the increase in salt content. It is expected to provide guidance for evaluation on salt expansion of the foundations of residual sulfate saline soil with high salt content in the northwest region of China. |
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| Keywords: | sulfate saline soil salt expansion drying shrinkage water content one time decrease single cooling |
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