Sulfate Saline Soil Low Temperature Compression Properties

Compressive deformation of the salty soil means the soil with natural water content will be compressed under the action of load. Measuring method of the compressibility of the salty soil is roughly coextensive with the non-salty soil, which can adopt consolidation test. Consolidation test is a important link of obtaining mechanical properties index of soil and coefficient of compressibility gained through the test is a key data to evaluating the compressibility of soil. Consisting of solid phase and liquid phase of the salty soil is different from the non-salty one. Eutectic salt in soil may exist as liquid phase, solid phase or both of them and these phases can interconvert because it is affected by temperature, Na₂SO₄ content, water content. Especially when temperature drops, Na₂SO₄ will crystallize and expand, namely salt expansion of soil. These particularities make soil sample put in environmental cabinet when consolidation test is going on. So soil sample can be compressed by temperature controlling system under a set temperature.From experiment, the formulae counting coefficient of compressibility of salty soil have been given. These formulae vary with four factors including water content, Na₂SO₄ content, initial dry unit weight and temperature. The laws of single factor effect and interaction between each factor on coefficient of compressibility of sulphate salty soil are analysized . It is proposed that the relation between coefficient of compressibility and each factor is a conic parabola.