原生微生物固化细粒硫酸盐渍土的细观特征及其强度变化机制

Microscopic characteristics and strength variation mechanism of indigenous microbial solidified fine-grained sulfate saline soil

为解决物理和化学方法改良盐渍土工程性质时工程耗能高、环境负效应扰动大的问题,利用高原寒区盐渍环境发育的原生脲解型微生物对细粒硫酸盐渍土进行固化试验,采用微观试验和三轴压缩试验对微生物固化盐渍土的强度特征进行了研究。结果表明:细粒硫酸盐渍土被微生物固化后,抗剪强度最高可提升2.9倍,增强机制由黏聚强度的提高程度所决定;固化土的初始切线模量和刚度得到提升,抗变形能力得到增强。该研究结果对增强固化土的稳定性、承载力等具有理论研究和实践指导意义。

Due to high energy consumption and significant environmental negative effects of physical and chemical methods for improving the engineering properties of saline soil,solidification experiments on the fine-grained sulfate saline soil are conducted by using indigenous urealytic microorganisms developed in saline environments in high-altitude cold regions.The strength characteristics of microbial solidified saline soil are studied by making use of microscopic tests and triaxial compression tests.The results indicate that the shear strength of fine-grained sulfate saline soil can be increased up to 2.9 times after being solidified by microorganisms.The enhancement mechanism is determined by the degree of improvement in adhesive strength.The initial tangent modulus and stiffness of the solidified soil are improved,and the anti deformation ability is enhanced.The research results have guiding significance for theoretical research and practice on the improvement of stability and bearing capacity of solidified soil.