摘要
采用自制三轴蠕变仪,在恒定围压分级增轴压的加压条件下完成了片麻岩三轴压缩蠕变试验。结合蠕变试验结果,提出了含有广义Kelvin单元体的岩石蠕变复合模型,最终利用不同应力水平下岩石蠕变试验曲线对蠕变参数进行辨识,确定了模型参数。研究结果表明:随着应力水平的不断提高,试样蠕变经历了衰减蠕变、稳态蠕变、加速蠕变三个阶段;试样在围压10MPa条件下,轴压达到150MPa时出现加速蠕变阶段,加速蠕变启动时间为11.56h;蠕变试验等时曲线显示片麻岩蠕变具有较好的线性特征;与试验结果对比显示,二单元广义Kelvin复合蠕变模型能够更加准确地描述片麻岩蠕变特性。研究结果对硬岩蠕变特性研究具有一定的参考意义。
Triaxial compression creep experiment of gneiss was carried out under the condition of constant confining pressure and stepwise increasing axial pressure by using a self-made triaxial creep apparatus.Combined with creep experimental results,a composite model of rock creep with generalized kelvin element was proposed.Finally,creep parameters were identified by using creep experimental curve of rock under different stress levels,and the parameters of the model were determined.Study results show that with the increase of stress level,the creep of specimen undergoes three stages,attenuation creep,steady creep and accelerated creep.Under the condition of confining pressure 10MPa,the accelerated creep stage occurs when the axial pressure reaches 150MPa,and the start-up time of accelerated creep is 11.56h;the isochronous curve of creep experiment shows that gneiss creep has better linear characteristics.Compared with experimental results,two-element generalized kelvin composite creep model can more accurately describe the creep characteristics of gneiss.Above results may provide reference for study of hard rock creep characteristics.
作者
张涛
梁冰
王俊光
李刚
詹辛慧
ZHANG Tao;LIANG Bing;WANG Jun-guang;LI Gang;ZHAN Xin-hui(Mining Institute,Liaoning Technical University,Fuxin 123000,Liaoning,China;Institute of Mechanics & Engineering,Liaoning Technical University,Fuxin 123000,Liaoning,China)
出处
《实验力学》
CSCD
北大核心
2019年第1期176-182,共7页
Journal of Experimental Mechanics
基金
国家自然科学基金(5157041488
51404130
51774165)资助
国家重点研发计划项目(2016YFC0600704)资助
