摘要
利用MTS 815.04试验系统对经过不同次数干湿循环的白云岩开展了不同围压的循环加卸载试验,从应力—应变曲线、峰值强度、动态弹性模量、能量演化和耗能比等方面,探讨了白云岩力学特性和能量演化规律。结果表明:(1)应力—应变曲线随干湿循环次数的增加表现出内凹的非线性特征;(2)循环荷载提高了白云岩的承载能力,循环荷载下的峰值强度超过了相同围压条件下常规压缩的峰值强度;(3)动态弹性模量在0.3σc、0.5σc和0.8σc应力水平下的变化可划分为强化阶段和弱化阶段,且随围压的增加而增大,随干湿循环次数的增加而减小;(4)总能量和弹性能在循环加卸载中表现出典型的阶梯式上升;(5)白云岩在首次干湿循环过程中表现出显著的压密效应,其耗能比高于同一应力水平下的其余循环加卸载过程,耗能比均值随围压和干湿循环次数的增加以及应力水平的提高而增大。该研究成果为复杂环境的岩石力学特性提供了理论依据,对矿山边坡的灾害防控具有重要的参考意义。
To examine the mechanical properties and energy evolution of dolomite subjected to dry-wet cycles and cyclic loading and unloading,a series of conventional compression tests were conducted using the MTS 815.04 test system.These tests were performed under varying confining pressures,specifically utilizing 0.3σc,0.5σc,and 0.8σc as the upper limits of the tertiary stress for hierarchical cyclic loading and unloading.The lower limit of the stress amplitude was set at 1 MPa,and the cyclic loading and unloading frequency was maintained at 0.8 Hz,with 30 cycles executed at each stress level.Triaxial cyclic loading and unloading tests were conducted on dolomite samples that had undergone different numbers of dry-wet cycles to analyze and discuss the stress-strain curves,peak strength,dynamic modulus of elasticity,energy evolution,and energy consumption ratio characteristics.The findings indicate that the stress-strain curves of dolomite subjected to dry-wet cycles exhibit a concave and non-linear nature,with hysteresis loops resembling a“curved moon”shape.Under cyclic loading and unloading,the peak strength surpasses that observed in conventional compression at identical confining pressures,with enhancements of 11.69%,12.81%,and 17.43%,respectively.The peak strength increases with rising confining pressure but decreases as the number of dry-wet cycles increases.Although total deterioration intensifies with more dry-wet cycles,the rate of increase diminishes,indicating a gradual weakening of the deterioration effect.The dynamic modulus of elasticity exhibits variable changes across different stress levels,showing a strengthening phase at a 0.3σc stress level and a weakening phase at 0.5σc and 0.8σc stress levels.Both total and elastic energies demonstrate a characteristic stepwise increase with escalating stress levels,with the highest energy dissipation ratio occurring during the first cycle at any given stress level.The mean energy dissipation ratio rises with increasing confining pressure,the number of dry-wet cycles,and stress levels.The findings of this study offer a theoretical foundation for understanding the mechanical properties of rocks in complex environments,and has great reference significance for the disaster prevention and control of mine slopes.
作者
侯国庆
王运敏
李小双
张锋
鲁俊
HOU Guoqing;WANG Yunmin;LI Xiaoshuang;ZHANG Feng;LU Jun(Shaoxing University,Shaoxing 312000,Zhejiang,China;State Key Laboratory of Safety and Health for Metal Mine,Ma’anshan 243000,Anhui,China;Sinosteel Ma’anshan Institute of Mining Research Co.,Ltd.,Ma’anshan 243000,Anhui,China;Changzhou University,Changzhou 213164,Jiangsu,China;Qilu Institute of Technology,Jinan 250200,Shandong,China)
出处
《黄金科学技术》
北大核心
2025年第4期865-876,共12页
Gold Science and Technology
基金
云南省中央引导地方科技发展项目“重要生态敏感区磷矿山固废充填保水绿色开采技术应用研究”(编号:202407AC110019)
国家自然科学基金项目“干湿—冷热—循环载荷耦合下高陡岩质边坡裂隙岩体的疲劳失稳机理研究”(编号:42477142)
“干湿交替—爆破振动耦合下含空区高陡岩坡力学响应特征及其失稳机理研究”(编号:42277154)
贵州省科技计划项目“复杂环境应力下难采胶磷矿露天转地下开采岩体响应特征研究”(编号:黔科合支撑〔2022〕一般229)
山东省高等学校青创人才引育计划“边坡安全管控与灾害预防技术创新团队”(编号:鲁教科函〔2021〕51号)
山东省自然科学基金项目“露井复合采动下岩体响应的演化特征及其破坏机制研究”(编号:ZR2022ME188)
山东大学“新高校20条”科研带头人工作室项目“干湿交替—爆破振动耦合作用下含高陡岩质边坡力学响应特征及其致灾机制研究”(编号:20228108)
常州大学高层次人才引进项目“降雨入渗与露井复合采动耦合作用下高陡岩质边坡岩体响应的演化特征及其致灾机制研究”(编号:ZMF24020037)联合资助。
关键词
岩石力学
白云岩
干湿循环
循环加卸载
动态弹性模量
能量演化
rock mechanics
dolomite
dry-wet cycle
cyclic loading and unloading
dynamic modulus of elasticity
energy evolution
