含盐量及含水量对氯盐盐渍土抗剪强度参数的影响

Influence of Salt Content and Water Content on the Shearing Strength Parameters of Chlorine Saline Soil

盐渍土作为一类特殊的工程地质体,其抗剪强度受环境因素的影响是复杂的。通过室内试验,分析不同含盐量和含水量条件下氯盐盐渍土抗剪强度的变化规律,研究含盐量、含水量对盐渍土抗剪强度的影响机理。研究表明:在含水量达到一定量时,随着CaCl2含量的增加,氯盐盐渍土的抗剪强度参数值是先减小后增大,达到最小值时的土体临界含盐量为10.36%;在含盐量一定的情况下含水量从8%增到10%时,抗剪强度参数值减小幅度比较大,而从10%增到15.56%时,抗剪强度参数值减小幅度明显变小;土中易溶盐相态的变化,从土颗粒间溶液的离子浓度和土体骨架作用两方面影响盐渍土的抗剪强度;当含盐量一定时,随着含水量的增大,土粒间离子的浓度逐渐减小,使得扩散层厚度增大,粘结力减小。

Saline soil can be treated as special engineering materials for containing soluble salt, so the influence of environmental factors on its shearing strength is complicated. In order to find the changing rules of chlorine saline soil＇s shearing strength with variable salt content and water content and discuss the mechanism of shearing strength influenced by salt content and water content, saline soil samples were tested in laboratory. The research results show that while water content reaches the constant, strength parameters diminishes initially and increases subsequently with the increasing of CaCl2 content in soil, and 10.36% is the limited salt content when shearing strength reaches the minimum. When salt content reaches the constant, the shearing strength parameters reduce obviously with the water content ranging from 8% to 10%. However, it reduces slightly with the water content ranging from 10% to 15.56%. The state changing of soluble salt affects saline soil＇s shearing strength due to change ion concentration among soil grain and soil framework. When salt content is fixed, the ionic concentration （no） among soil grain reduces gradually with the increasing of water content, resulting in the increasing of diffusion layer and the reducing of the cohesion.