摘要
隧道开挖、矿山开采等工程中均涉及有岩石应力周期性压缩和拉伸现象,施工条件产生的力学效应对岩石结构影响显著。为研究不同加卸载速率下岩石的变形破坏特征,设计了砂岩在单轴条件下非等同加卸载速率循环荷载试验,基于应力-应变曲线、滞回环、残余应变等角度深入分析了砂岩岩体在循环荷载下的损伤、失稳劣化演化规律。结果表明:和单调加载条件对比,循环荷载对岩样的峰值应力有加强作用。横幅循环荷载残余应变与循环次数呈对数函数相关,分级循环荷载中每一级的上限应力对应变的改变量要大于下限应力对应变的改变量;残余应变与循环次数拟合结果为同一斜率的线性相关函数;加载方式对岩样弹性模量大小有一定影响,且加卸载速率一致时对其影响最大。
Tunnel excavation,mining and other projects involve the phenomenon of periodic compression and tension of rock stress.The mechanical effect produced by construction conditions has a significant impact on rock structure.In order to study the deformation and failure characteristics of rock under different loading and unloading rates,the cyclic load test of sandstone at different loading and unloading rates under uniaxial conditions is designed.Based on the stress-strain curve,hysteresis loop and residual strain,the evolution law of damage,instability and deterioration of sandstone rock mass under cyclic load is deeply analyzed.The results show that compared with the monotonic loading condition,the cyclic load can strengthen the peak stress of rock samples.The residual strain of banner cyclic load is related to the number of cycles in a logarithmic function.In the graded cyclic load,the change of the upper limit stress to the strain is greater than that of the lower limit stress to the strain.The fitting result of residual strain and cycle times is a linear correlation function with the same slope.The loading mode has a certain influence on the elastic modulus of rock samples,and the same loading and unloading rate has the greatest influence on it.
作者
任洋
吴云峰
REN Yang;WU Yunfeng(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《有色金属工程》
CAS
北大核心
2022年第11期111-119,共9页
Nonferrous Metals Engineering
基金
国家重点研发计划项目(2018YFC0604601)。
关键词
岩石力学
循环加卸载
残余应变
弹性模量
rock mechanics
cyclic loading and unloading
residual strain
elastic modulus
