不同酸碱度对改良红黏土力学性质及结构的影响

Research on mechanical properties and microstructure of improved Guilin red clay under different pH environment

红黏土在土类划分上属于特殊性土,由于其特殊的成因过程及成因环境,工程性质也有很大区别。为了研究地下水环境酸碱度对改良土的强度影响,通过将改良土体浸泡到不同酸碱度的溶液中,测试改良土的力学性质,研究不同掺量、浸泡时间和溶液酸碱度对改良红黏土的影响和作用机理。再通过电镜扫描,研究改良红黏土的微观结构,探讨其与力学性质改善的关系。试验结果表明,从宏观上,在酸性环境下改良土凝聚力均随浸泡时间的增长而减小。从微观上,土粒的搭接形式、搭接程度以及颗粒间的胶结程度决定了土体的物理力学性质,而酸碱环境使改良红黏土结构发生变化,土粒间黏结程度得到改善。

Due to special formation process and environment,red clay belongs to peculiar soil with different engineering characteristics. We soak the improved soil into different p H of solutions to study the mechanical properties and action mechanism of improved soil under different dosage,soaking time and p H values. By electron microscopy scanning,we explore the microstructure of modified Guilin red clay and its relationship with mechanical properties. The results show that on macroscopic view,the cohesive force of improved red clay reduces with the growth of soaking times under acid environment. From microscopic view,the overlapping degree,overlapping way as well as cementation forms of soil particle determine the physical mechanical property of soil. Under various p H environments,the red clay structure changes,and the degree of cementation between soil particles is improved.