摘要
准确预测岩体失稳破坏可为岩体支护设计提供依据。通过单轴循环加卸荷试验探究裂隙倾角在岩体各受荷过程中对能量演化规律的影响,揭示岩体变形破坏过程中能量演化的本质特征。研究表明:加荷初期,弹性能比例为40%~45%,中期为55%左右,临近破坏时为60%~65%,能量比例变化速率和裂隙倾角关系密切。能量密度随荷载增加而增加,裂隙倾角影响能量密度的变化速度;能量密度比例趋势转折越明显,表明岩体越易破坏;耗散能密度增减过程与岩石受荷起裂破坏过程拟合程度较高;裂隙岩体对能量的吸收能力随裂隙倾角的增长先增加后减小。裂隙倾角对能量演化的影响呈非线性,不同受荷阶段的能量关系存在显著特征,此特征能够较好预警岩体失稳破坏。
Prediction of instability and failure of rock mass can provide a basis for the design of rock mass support. The effect of fissure inclination on the energy evolution of rock mass is studied by cyclic loading and unloading. The process of energy evolution revealed the nature of rock deformation and breakage. The study results show that: the elastic energy ratio is about 40% ~45% at the beginning of the loading,approximately 55% at the middle stage,and 60% ~ 65% at the later stage; The variation rate of elastic energy ratio has a close relation with the fissure inclination. The energy density increases with the increase of load,and the fissure inclination affects the variation rate of energy density; The more obvious the transition of the ratio of energy density is,the closer the rock mass is to destruction; The increase and decrease of dissipation energy density has a high correlation with the failure process of rock mass; The energy absorption capacity of fractured rock mass increases first and then decreases with the increase of inclination,showing a nonlinear relationship between the fracture angle and the energy evolution. These relations are distinguished in different stages,thus it can be an early indicator to instability and failure of rock mass.
引文
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