吹填软土CU三轴剪切应力松弛特性试验研究

发布时间：2018-04-28 14:23

本文选题：吹填软土 + 三轴剪切　；参考：《岩土力学》2017年11期

【摘要】：应力松弛与蠕变二者机制不同,不能简单复制。CU三轴剪切试验可以对许多工况进行模拟,而这些工况中可能包含了一定程度的应力松弛现象,由应力松弛导致的工程事故时有发生。天津滨海吹填软土具有显著的流变特性,以天津滨海吹填软土为研究对象,使用WF应力路径三轴仪,对土样进行固结不排水三轴剪切应力松弛试验。试验结果表明:应力松弛过程可分为快速、慢速和稳定3个阶段;一定范围内,应力松弛速率随初始松弛应变增大而增大;偏应力与时间对数之间存在近似线性关系;应力松弛对总抗剪强度指标几乎无影响,但使有效黏聚力c'减小,有效内摩擦角φ'增大。最后对试验数据进行了归一化和拟合,推导并验证了能够反映吹填软土应力松弛特性的应力-应变-时间关系模型。其研究结果对天津滨海吹填软土的流变性进行了补充,可为相关工程事故的防治提供理论参考。
[Abstract]:The mechanism of stress relaxation and creep is different. The triaxial shear test of .CU can not be simply copied to simulate many working conditions, which may contain a certain degree of stress relaxation. Engineering accidents caused by stress relaxation occur from time to time. Tianjin Binhai dredged soft soil has remarkable rheological properties. The undrained triaxial shear stress relaxation test was carried out by using WF stress path triaxial apparatus. The experimental results show that the stress relaxation process can be divided into three stages: fast, slow and stable, the stress relaxation rate increases with the increase of initial relaxation strain in a certain range, and there is an approximate linear relationship between the deviant stress and the logarithm of time. Stress relaxation has little effect on the total shear strength, but it decreases the effective cohesion C 'and increases the effective internal friction angle 蠁'. Finally, the experimental data are normalized and fitted, and the stress-strain-time relationship model which can reflect the stress relaxation characteristics of soft soil is deduced and verified. The research results complement the rheological behavior of Tianjin coastal fill soft soil and can provide a theoretical reference for the prevention and treatment of related engineering accidents.
【作者单位】：天津城建大学天津市软土特性与工程环境重点实验室;中国水电基础局有限公司;
【基金】：国家自然科学基金项目(No.41372291) 天津市科技计划项目(No.15JCZDJC40600,No.15ZCZDSF00220)~~
【分类号】：TU447

【相似文献】