摘要
为探讨含盐量对盐渍土抗剪强度的影响和结构效应,依托青海柴达木盆地某水资源配置工程,以级配和结构不同的粉质黏土类、砂质粉土类硫酸盐渍土为研究对象,通过室内三轴试验,分析两类盐渍土在不同硫酸盐含量和不同围压下的力学响应特征及变形特性,研究其抗剪强度参数随含盐量增加的变化规律,探讨硫酸盐渍土抗剪强度参数的含盐量效应和结构效应.结果表明,含盐量对盐渍土抗剪强度参数的影响存在阈值含盐量现象,即含盐量的影响具有分段性,两类盐渍土的黏聚力c和内摩擦角φ随含盐量的变化均呈相反的变化规律.以阈值含盐量为界,随着含盐量的增加,粉质黏土类盐渍土的c先减后增、φ先增后减;砂质粉土类盐渍土的c先增后减,φ先减后增.粉质黏土和砂质粉土在内部结构上的差异,导致土颗粒与盐分间的相互作用机理不同,使得抗剪强度参数对含盐量的变化表现出不同的响应规律,具有显著的结构效应.
To investigate the effect of salt content on the shear strength and structural effects of saline soils,based on a water resource allocation project in Qaidam Basin,Qinghai,the mechanical response characteristics and deformation properties of two types of saline soils with different sulfate content and different surrounding pressure were analyzed through a series of indoor triaxial tests,and the change of shear strength parameters with increasing salt content was studied.The change of shear strength parameters with increasing salt content was investigated,and the effects of salt content and structure on shear strength parameters of sulfate saline soils were discussed.The results showed that there was a threshold salt content phenomenon,i.e.the effect of salt content on the shear strength parameters of saline soils was segmental.The cohesion c and the angle of internal friction φ of both types of saline soils showed opposite patterns of variation with the salt content:with the threshold salt content as the boundary,c decreased and then increased and φ increased and then decreased with increasing salt content,while c increased and then decreased and φ decreased and increased with increasing salt content for the powdered clay type of saline soils.The internal structure of the powdered clay and the powdered fine sand soils was different,resulting in different mechanisms of interaction between the particles and salt in the two types of soils,and the shear strength parameters of the two types of saline soils showed different response patterns to changes in salt content,with significant structural effects.
作者
李积锋
谢文斌
刘高
覃漭
LI Ji-feng;XIE Wen-bin;LIU Gao;QIN Mang(Water Conservancy and Hydropower Survey,Planning,Design and Research Institute Co.,Ltd.of Qinghai,Xining 810000,China;College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China)
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第6期812-816,823,共6页
Journal of Lanzhou University(Natural Sciences)
关键词
盐渍土
含盐量
抗剪强度参数
硫酸盐
结构效应
saline soil
salt content
shear strength parameter
sulphate
structural effect
