摘要
能量的耗散与释放是岩石变形破坏的本质。基于MTS815 Flex Test GT岩石力学试验平台,通过室内3轴卸荷试验和数学物理分析方法,揭示了大理岩在高围压3轴卸荷条件下的应力应变关系及能量变化特征。结果表明:初始围压的增大将显著提升岩样峰值强度时的可释放应变能以及最终总能量;随着围压的增大,岩样所吸收的能量变化的快慢程度随着偏应力变化而有所减缓;峰值强度时岩样可释放应变能占总能量的比例随着围压的增大而急剧增大,而残余强度时所吸收的总能量几乎全部转化为耗散能;大理岩能量指标存在明显的围压效应,即峰值总能量和残余总能量随着围压增大而显著提高,且具有良好的线性关系。
The dissipation and release of energy are the essence of rock's deformation and failure.Based on the MT815 servo-controlled test machine,laboratory triaxial unloading experiments and mathematical physics analysis were adopted to obtain the characteristics of energy change and the stress-strain relationship of marble under unloading and high confining pressure.The results showed that the releasable strain energy at the peak strength and total energy of rock samples could both be significantly enhanced with the increase of the initial confining pressure.With the increase of the confining pressure,the slope of the energy change reduces with deviatoric stress curve.As the confining pressure increasing,the ratio of releasable strain energy to total energy at the peak strength would increase sharply,and all of the total energy is almost absorbed into the dissipated energy when attaching the residual strength.Meanwhile,marble energy index has obvious effect of confining pressure.Both peak and residual total energy increase sharply with the enlargement of the confining pressure,and has good linear relationship with it.
出处
《四川大学学报（工程科学版）》
CSCD
北大核心
2014年第S2期60-64,共5页
Journal of Sichuan University (Engineering Science Edition)
基金
国家自然科学基金资助项目(51079092)
四川省科技支撑计划资助项目(2008SZ0163)
关键词
岩石力学
大理岩
3轴卸荷
高围压
能量特征
变形破坏
rock mechanics
marble
triaxial unloading
high confining pressure
energy analysis
deformation failure
