洗盐对碳酸盐渍土的物理特性影响

Effect of Salt Washing on Physical Properties of Carbonate Saline Soil

洗盐是重塑碳酸盐渍土的一个重要试验过程,为研究重塑碳酸盐渍土洗盐前后物理性能及部分力学性能的变化,选取了松嫩平原杜尔伯特地区典型碳酸盐渍土(粉质黏土),对其进行洗盐处理,并测定其洗盐前后的含盐量、液塑限、最佳干密度及最优含水量,同时对洗盐前后的土体进行三轴试验以测定其抗剪强度、黏聚力和内摩擦角的变化。研究发现,洗盐导致土体含盐量、最优含水量和粘聚力下降,盐渍土的液限由30.1%降为20.2%,塑限由15.6%降为11.3%,而抗剪强度和内摩擦角增大;同时土体级配发生变化,土体也由粉质黏土变成了粉土。

Salt washing is an important test process for remolding carbonate saline soil.In order to study the changes of physical properties and partial mechanical properties of remolded carbonate saline soil before and after salt washing,the typical carbonate saline soil(silty clay)in Durbert area of Songnen Plain was selected for salt washing treatment.The salt content,liquid and plastic limit,optimal dry density and optimal water content before and after salt washing were determined.At the same time,the triaxial test was carried out to determine the changes of shear strength,cohesion and internal friction angle before and after salt washing.It was found that salt washing lead to the decrease of soil salt content,optimal water content and cohesion.The liquid limit of saline soil decreased from 30.1% to 20.2%,and the plastic limit decreased from 15.6% to 11.3%.The shear strength and internal friction angle increased.At the same time,the soil gradation changed,and the soil also changed from silty clay to silty soil.