摘要
针对实际工程中不同部位土体所经历的应力路径不同的问题,以研究不同含水率、不同应力路径下贵州红黏土的力学特性为目的,选取实际工程中典型的三种应力路径,设计了采用K_0固结方式的不同含水率的三轴固结不排水试验。结果表明:不同的含水率及不同的应力路径对贵州红黏土的力学特性有很大的影响,红黏土的水敏性及对应力路径的敏感性都与其自身的结构性有很大关系;含水率及应力路径对红黏土抗剪强度指标的影响主要都表现在对黏聚力的影响上,而对内摩擦角的影响较小;坚硬、硬塑状态的红黏土在卸荷状态下达到抗剪强度峰值时的变形值最小,而含水率较高的红黏土在卸荷状态下的抗剪强度最差,在实际工程中该部分往往是发生变形破坏的突破点,应重点加强对该部分土体的加固与治理。研究成果对今后红黏土基坑的支护设计与计算及相关的数值模拟等具有参考价值。
Aiming at the problem experienced in the actual construction project that the stress paths in different parts of soil mass are different and taking the study on the mechanical characteristics of the red clay in Guizhou under the conditions of different moisture contents and different stress paths as the objective, three kinds of stress paths in the actual construction are selected, and then the undrained triaxial consolidation test on different moisture contents are designed with K0 consolidation mode. The result shows that different stress paths and different moisture contents have great impacts on the mechanical characteristics of the red clay in Guizhou whileboth the water-sensitivity of the red clay and its sensitivity to stress path are largely related to its self-structure. The impacts from moisture content and stress path on the shear strength index of the red clay mainly exhibit at the impact on the cohesion, while the impact on the internal friction angle is less. The deformation value of the red clay in a hard and hard plastic state is the least when it reaches the peak value of shear strength under the unloading state, while the shear strength of the red clay with higher moisture content is worst under the unloading state, which is often the breakthrough point for deformation and failure, thus reinforcement and relevant treatment must be emphatically made on that part of soil mass. The study result has certain referential value for design, calculation and relevant numerical simulation for the supporting of the red clay foundation pit in the days to come.
作者
陈筠
高彬
张瑶丹
陈泰徐
杨恒
CHEN Jun;GAO Bin;ZHANG Yaodan;CHEN Taixu;YANG Heng(Guizhou Institute of Technology, Guiyang 550003 , Guizhou, China;Resources and Environmental Engineering College, Guizhou University, Guiyang 550025 , Guizhou, China)
出处
《水利水电技术》
北大核心
2019年第2期53-60,共8页
Water Resources and Hydropower Engineering
基金
贵州省地质灾害监测预警与决策支持平台建设(Z113278)
贵州省科学技术基金"既有地基红黏土力学时效特性及本构模型修正"(黔科合J字[2015]2033号)
关键词
红黏土
含水率
应力路径
K0固结
力学特性
red clay
moisture content
stress path
K0 consolidation
mechanical characteristics
