摘要
为了研究岩石在循环加卸载下的力学特性及能量损伤演化规律,设计了5种花岗岩三轴循环加卸载试验。基于试验结果,详细分析了不同围压的循环加卸载模式下的总能量、弹性应变能和耗散能的演化特征及相互关系,建立了岩石损伤耗散能与循环加载次数及围压的耦合演化方程。结果表明:①当载荷小于峰值应力时,加载阶段的弹性模量小于卸载阶段的弹性模量;②峰值应力前,载荷所产生的能量主要表现为弹性应变能,而峰值应力后,载荷所产生的能量主要表现为耗散能;③随着围压的增加,岩石弹性应变能及耗散能增加;④循环加卸载作用下,岩石的耗散能与围压及加卸载循环次数有明显相关性,可以用非线性曲面进行拟合,可为定量分析循环加卸载过程中岩石损伤提供参考。
To analyze the evolution law of mechanical properties and energy during the cyclic loading and unloading process,five kinds of granite triaxial cyclic loading and unloading experiments have been performed.Based on the experimental results,the evolution characteristics and their interrelationship of total absorption energy,elastic strain energy and dissipated energy under different confining pressure have been analyzed in detail,and the coupling evolution equation of rock damage dissipated energy changes with cycles loading and unloading times and confining pressure are established.The results show that:①When the load is less than the peak stress,the elastic modulus in the loading stage is smaller than that in the unloading stage;②Before the peak stress,the energy generated by the load is mainly shown as elastic strain energy,while after the peak stress,the energy generated by the load is mainly expressed as dissipated energy;③As the confining pressure increases,rock elastic strain energy and dissipated energy increases;④Under cyclic loading-unloading,the dissipated energy of the rock has a significant correlation with the confining pressure and the cycle loading and unloading times.Non-linear curved surfaces can be used for fitting the relationship.This finding can provide a basis for quantitative analysis of rock damage during cyclic loading and unloading.
作者
杨计先
罗明坤
张晓悟
黄宁
侯胜军
YANG Jixian;LUO Mingkun;ZHANG Xiaowu;HUANG Ning;HOU Shengjun(Zhangcun Coal Mine,Shanxi Lu'an Environmental Energy Development Co.,Ltd.,Changzhi 046031,China;School of Mining,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory of Coal Resources and Safe Mining,Xuzhou 221116,China;Sanhui Second Mine,Chongqing Tianfu Mining Co.,Ltd.,Hechuan 401535,China)
出处
《采矿与岩层控制工程学报》
北大核心
2021年第3期87-94,共8页
Journal of Mining and Strata Control Engineering
基金
煤炭资源与安全开采国家重点实验室自主研究课题资助项目(SKLCRSM2020X05)。
关键词
循环加卸载
力学特征
能量演化
损伤
cyclic loading and unloading
mechanical characteristics
energy evolution
damage
作者简介
杨计先(1969-),男,山西高平人,高级工程师,主要从事岩石力学与岩层控制方面的研究工作。E-mail:471131584@qq.com。
