不同上限应力循环加卸载作用下硬岩损伤力学特性与能量演化研究  

Damage Mechanical Properties and Energy Evolution of Hard Rock Under Cyclic Loading and Unloading Effects with Different Upper Limit Stresses

作　　者：郝建平 董春亮 姚梦圆[1] HAO Jianping;DONG Chunliang;YAO Mengyuan(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Mechanics and Optoelectronic Physics,Anhui University of Science and Technology,Huainan,Anhui 232001,China;State Key Laboratory of Response to Mining Activity and Disaster Prevention and Control of Deep Coal Mining,Anhui University of Science and Technology,Huainan,Anhui 23200l,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南市232001 [2]安徽理工大学力学与光电物理学院,安徽淮南市232001 [3]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南市232001

出　　处：《矿业研究与开发》2025年第3期119-127,共9页Mining Research and Development

基　　金：国家自然科学基金项目(52074006)。

摘　　要：地下岩体常受外部因素影响,反复的循环加卸载会导致岩石内部裂纹不断增多,局部应力环境亦发生变化。因此,对砂岩进行了不同上限应力值的三轴分级循环加卸载试验,分析得到了不同上限应力值下砂岩的损伤力学特性以及能量演化规律。试验结果表明:在分级循环加卸载的条件下,砂岩的应力-应变曲线呈现出滞回环和向下弯曲的特征,并且随着应力的增大,滞回环逐渐扩大。在不同上限应力的循环加卸载作用下,随着循环次数的增加,砂岩的轴向弹性应变和轴向塑性应变与循环次数呈线性关系,而轴向塑性应变发生骤降则表明砂岩内部孔隙裂缝被快速压实。同时,在循环过程中输入能与弹性能曲线非常相似,呈现出近似指数曲线的上升趋势。耗散能在初始循环阶段增长相对缓慢,这表明砂岩原有裂纹发生压缩与闭合;而在循环中期,耗散能呈现出近似线性的增长趋势,这表示岩样正处于裂纹稳定扩展阶段。耗能比在初始循环阶段呈现骤降的趋势,而在循环中期阶段耗能比曲线则保持近似水平的趋势。此外,在分级循环加卸载条件下,砂岩的损伤度与循环次数之间呈现线性关系,说明荷载循环次数对砂岩的损伤度有较大的影响。The underground rock body is often affected by external factors,after repeated cycles of loading and unloading,it will lead to the increase of internal cracks in rock and the change of local stress environment.Therefore,the triaxial graded cyclic loading and unloading tests with different upper limit stresses were carried out on sandstone,and the damage mechanical properties and the laws of energy evolution of sandstone were obtained.The test results show that under the conditions of graded cyclic loading and unloading,the stress-strain curve of sandstone is characterized by hysteresis loops and downward bending,and the hysteresis loops are gradually enlarged with the increase of stress.Under the cyclic loading and unloading with different upper limit stresses,as the number of cycles increasing,the axial elastic strain and axial plastic strain of sandstone show linear relationships with the number of cycles,while the sudden drop of axial plastic strain indicates that the internal pore cracks of sandstone are compacted rapidly.Meanwhile,the input energy and elastic energy curves are very similar during the cycling process,showing an upward trend of nearly exponential curve.Dissipation energy grows relatively slowly in the initial cycling stage,which indicates that the original cracks in the sandstone are compressed and closed;while in the mid-cycling stage,the dissipation energy shows a nearly linear growth trend,which indicates that the rock samples are in the stage of stable expansion of the cracks.The dissipation energy ratio shows a sudden decrease in the initial cycling stage;while in the mid-cycling stage,it maintains an approximate horizontal trend.In addition,under the graded cyclic loading and unloading,there is a linear relationship between the degree of damage to sandstone and the number of cycles,indicating that the number of load cycles has a significant impact on the degree of damage to sandstone.

关 键 词：砂岩 力学特性 能量演化 分级循环加卸载 上限应力 

分 类 号：TD325[矿业工程—矿井建设] TU45[建筑科学—岩土工程]