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详细总结岩石应力门槛值(起裂强度ci?、损伤强度cd?和峰值强度f?)的物理意义和计算方法,以花岗岩和大理岩为研究对象进行不同围压的常规三轴试验,计算分析ci?,cd?和f?值,以及各个门槛值对应的轴向应变、侧向应变和体积应变的变化规律,重点讨论轴向应变和侧向应变的特点和产生机制,分析结果发现:花岗岩的cc?/f?,ci?/f?,cd?/f?分别位于0.10~0.19,0.40~0.59,0.77~0.82区间内,大理岩相应的应力比位于0.10~0.25,0.47~0.64,0.82~0.92内,不同岩石或相同岩石门槛值应力比的差异可能由于矿物成分、赋存环境、开挖损伤造成;2种岩石应力门槛值及各自对应的轴向应变随围压近似呈线性递增,并且应力和轴向应变随围压的变化曲线非常相似;侧向应变在达到cd?之前增长缓慢,在达到cd?之后急剧增加,而轴向应变在整个加载过程稳步增加;围压、cd?和对应的损伤体积应变存在内在关联性,相互关系可用线性或二项式拟合。
The physical meaning and calculation method of rock stress thresholds (initiation strength ci?, Damage strength cd? And peak strength f?) Are summarized in detail. Conventional triaxial tests with different confining pressures are performed on granite and marble, and the calculation and analysis ci ?, cd? and f? values, as well as the variation rules of axial strain, lateral strain and volumetric strain corresponding to each threshold, focusing on the characteristics and mechanism of axial strain and lateral strain. The results show that granite , Respectively. The corresponding stress ratios of marble are 0.10-0.25,0.47-0.64 and 0.82, respectively, which range from 0.10 to 0.19, from 0.40 to 0.59 and from 0.77 to 0.82, respectively. ~ 0.92, the differences of threshold stress ratios of different rocks or same rocks may be caused by mineral composition, occurrence environment and excavation damage. The stress thresholds and corresponding axial strains of two kinds of rocks increase linearly with the confining pressure approximately linearly, And the variation curves of stress and axial strain with confining pressure are very similar. The lateral strain grows slowly before reaching cd? And increases sharply after reaching cd ?, while the axial strain increases steadily throughout the loading process. And the corresponding damage volume strain inherent correlation, phase Relationship may be linear or binomial fit.