郑州大学学报（工学版）2024，Vol.45Issue(1)：98-106,9.DOI:10.13705/j.issn.1671-6833.2024.01.001
含泥量对砂类硫酸盐渍土工程特性的影响分析
Analysis of the Influence of Mud Content on the Engineering Characteristics of Sand Sulfate Saline Soil
摘要
Abstract
In order to study the influence of mud content on salt swelling and mechanical properties of sand sulfate soils,sand sulfate soils with different fine-grained soil content were manually configured.Based on the unidirection-al freezing salt swelling test with 1％and 3％salt content,sand samples with fine-grained soil mass fraction of 5％,15％,and 30％were selected to conduct triaxial shear tests at constant and low temperature.The results showed that with the conditions of this test,the freezing temperature of sand sulfate saline soil of different levels was within the range of-0.7--0.1 ℃.When the pore solution concentration of the soil samples reached saturation above the freezing temperature,salt crystals could first be generated in the cooling process.With the condition of 1％salt content,the initial swelling temperature of sand samples with high fine-grained soil content(≥30％)was in the range of 4-9 ℃,while the initial swelling temperature of sand samples with low fine-grained soil content was near 0 ℃.The swelling temperature of 3％salt content sand sample was 20-23 ℃.The process of salt frost heave was inseparable from the participation of free water.The test water content and fine-grained soil content had a significant effect on salt frost heave by influencing the content of free water in the soil.In terms of mechanical properties,with the increase of the content of fine-grained soil,the shear strength of sand sulfate soils increased first and then decreased,and the fine-grained soil changed from enhancing friction to"lubrication"between particles.In addition,after freezing,the sand was transformed into a"soil-salt-ice skeleton structure"with a stronger bearing capacity,and the shear strength increased greatly,showing obvious brittle failure characteristics.Affected by relative temperature,the failure stress of frozen sand decreased first and then increased with the increase of salt content.关键词
砂类土/盐渍土/盐胀试验/三轴剪切试验/细粒土含量/SEM试验Key words
sand soil/saline soil/salt swelling test/triaxial shear test/fine-grained soil content/SEM test分类
建筑与水利引用本文复制引用
张莎莎,张超,王旭超,赵彦虎..含泥量对砂类硫酸盐渍土工程特性的影响分析[J].郑州大学学报（工学版）,2024,45(1):98-106,9.基金项目
国家自然科学基金资助项目(42101126) （42101126）
青海省交通运输厅科技项目(2020-02) （2020-02）
