摘要
为探究加筋角度与结构剪切特性之间的关系,采用大型循环剪切仪开展多角度土工格栅加筋土循环剪切试验,探究加筋角度和循环荷载对加筋细粒含量土剪切特性的影响,分析循环剪切过程中及加筋循环后直剪加筋细粒含量土的剪切性能变化。结果表明:不同角度土工格栅加筋细粒含量土剪切应力具有差异性,单向直剪试验中,30°加筋角度下,加筋细粒含量土剪切强度最大;法向应力为300 kPa时,6种角度(30°、60°、90°、120°、150°、180°)加筋界面均呈现循环剪切硬化的特征,180°加筋角度下,循环剪切应力峰值最大;剪切应力和剪切刚度随循环次数呈正相关关系,界面阻尼比随循环周期发展变化趋于平缓;不同循环幅值和法向应力下,30°加筋角度下细粒含量土呈现弱剪切硬化现象,随循环幅值或法向应力增加,土工格栅开始受力拉动上下土体,剪切应力增幅提高。
In order to explore the relationship between reinforcement angle and structural shear characteristics, the multi-angle cyclic shear test of geogrid-reinforced soil is carried out with large-scale cyclic shear apparatus, and then the influences from the reinforcement angle and the cyclic loading on the shear characteristics of the geogrid-reinforced soil are studied, while the changes of the shear performances of the directly sheared soil with fine grain content during cyclic shear and after reinforcing cycle are analyzed as well. The results show that the shear stresses of the geogrid-reinforced soil at different angles are different. In the unidirectional direct shear test, the shear strength of the geogrid-reinforced soil is the maximum under the reinforcement angle of 30°. When the normal stress is 300 kPa, the reinforced interfaces under 6 reinforcement angles(30°、60°、90°、120°、150°、180°) are all characterized by cyclic shear hardening, while the peak cyclic shear stress is the maximum under the reinforcement angle of 180°. The shear stress and shear stiffness are positively correlated with the number of cycles and the interface damping ratio tends to be flat with the development of cycle period, while the soil with fine grain content under the reinforcement angle of 30° exhibits weak shear hardening under different cyclic amplitudes and normal stresses. With the increase of cyclic amplitude or normal stress, the geogrid starts to be stressed to pull the upper and the lower soil masses along with increase of the increasing amplitude of shear stress.
作者
李丽华
屠娴哲
刘帅帅
黄少平
周鑫隆
LI Lihua;TU Xianzhe;LIU Shuaishuai;HUANG Shaoping;ZHOU Xinlong(School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,Hubei,China;Hubei Ecological Road Research and Engineering Center,Wuhan 430068,Hubei,China)
出处
《水利水电技术（中英文）》
北大核心
2022年第9期197-209,共13页
Water Resources and Hydropower Engineering
基金
武汉市应用基础前沿项目(2020020601012278)
国家自然科学基金项目(52108315)
湖北工业大学杰出人才基金项目(XJ2021000501)。
关键词
加筋角度
循环剪切特性
抗剪强度
直剪试验
加筋细粒含量土
reinforcement angle
cyclic shear characteristics
shear strength
direct shear test
reinforced soil with fine grain content
