重塑黄土的往返加卸载真三轴试验研究  

Cyclic loading and unloading true triaxial tests on remolded loess

作　　者：邵帅[1] 张佳庆 邵生俊[1,2,3] 宋佳瑶 严广艺[4] 朱学亮 SHAO Shuai;ZHANG Jiaqing;SHAO Shengjun;SONG Jiayao;YAN Guangyi;ZHU Xueliang(Institute of Geotechnical Engineering,Xi’an University of Technology,Xi'an 710048,China;State Key Laboratory Base of Eco-Hydraulic Engineering in Arid Area,Xi’an University,Xi'an 710048,China;Shaanxi Key Laboratory of Loess Mechanics and Engineering,Xi’an University,Xi'an,Shaanxi 710048,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,China)

机构地区：[1]西安理工大学岩土工程研究所,陕西西安710048 [2]西安理工大学西北旱区生态水利国家重点实验室,陕西西安710048 [3]西安理工大学陕西省黄土力学与工程重点实验室,陕西西安710048 [4]中铁第一勘察设计院集团有限公司,陕西西安710043

出　　处：《岩土工程学报》2024年第7期1491-1497,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52108342);陕西水利科技计划项目(2021 slkj-12);陕西省自然科学基础研究计划联合基金项目(2019JLP-21);西安理工大学博士启动金(107-451122001)。

摘　　要：针对不同应力路径往返加卸载条件下黄土累积塑性应变发展特性,以重塑黄土为研究对象,利用真三轴仪开展不同应力路径的往返加卸载试验研究,探究不同应力路径、应力幅值下黄土的循环应力时程曲线、滞回曲线、骨干曲线及累积塑性应变曲线的影响规律。揭示了应力路径对重塑黄土力学特性的影响,描述了各主应力与中主应力比b和应力幅值的相关性,提出了重塑黄土的滞回曲线近似呈椭圆形,长轴斜率随中主应力比b值的增大而增大,随应力幅值的增大而减小;随着中主应力比b值的增大,循环应力-应变骨干曲线随之硬化,累积塑性应变曲线依次降低,且累积塑性应变发展更早的进入平缓阶段,为解决相关黄土工程问题提供了参考。Aiming at the development characteristics of cumulative plastic strain of loess under different stress paths under cyclic loading and unloading conditions,the remolded loess is taken as the research object,and the round-trip loading and unloading tests under different stress paths are conducted using a true triaxial apparatus to explore the influences of different stress paths and amplitudes on the cyclic stress time-history curve,hysteresis curve,backbone curve and cumulative plastic strain curve of loess.The results reveal the effects of the stress paths on the mechanical properties of the remolded loess,describe the correlation among each principal stress,ratio of the intermediate principal stress and the stress amplitude,and the hysteresis curve of the remolded loess is proposed to be approximately elliptical,with the slope of the major axis increasing with the increase of the ratio of the principal stress and decreasing with the increase of the stress amplitude.As the value of the ratio of the principal stress ratio increase,the backbone curve of cyclic stress-strain hardens accordingly,the cumulative plastic strain curve decreases in sequence,and the cumulative plastic strain develops earlier and enters a gentle stage.The research results provide a reference for solving the relevant problems in loess engineering.

关 键 词：真三轴仪 循环应力 中主应力比 滞回曲线 骨干曲线 累积塑性应变 

分 类 号：TU41[建筑科学—岩土工程]