Effect of the density and inclination of joints on the strength and deformation properties of rock-like specimens under uniaxial compression
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摘要: 通過預制張開節理類巖石試件,在單軸壓縮條件下,研究節理密度及傾角的組合作用對試件強度和變形特征的影響.試驗結果表明:(1)隨著節理傾角的增大,應力-應變曲線由多峰值轉變為單峰值,試件脆性增強,延性減弱;(2)節理密度對當量峰值強度的影響與節理傾角大小有關,對當量彈模的影響呈“V”形變化,即當量彈模隨著節理密度的增大呈現先減小后增大的變化規律;(3)當量彈模隨節理傾角的增大而增大,在節理傾角為90°的時候達到最大值,為完整試件彈性模量的70%~80%;(4)節理傾角對多節理類巖石試件當量峰值強度和當量彈性模量的影響大于節理密度的影響.對試驗結果進一步分析發現:節理密度及節理傾角與應力-應變曲線、當量峰值強度及當量彈性模量之間的關系,其變化規律與試件的破壞過程息息相關,其破壞模式可分為張拉破壞、剪切破壞和復合破壞.Abstract: The effects of the combination of joint density and inclination on the strength and deformation characteristics of rocklike specimens containing open joints were studied by using uniaxial compression tests. The following conclusions were made:with the increase of joint inclination, the stress-strain curve changes from a multi-peak value to a single peak value and the brittleness of the specimen enhances, whereas the ductility of the specimen weakens. The influence of joint density on the unified peak strength is related to the size of joint inclination, and the effect of joint density on the unified modulus shows a "V" shape, namely, the unified elastic modulus first decreases and then increases with the increase of joint density. With the increase of joint inclination, the unified elastic modulus increases gradually and its maximum value, which achieves 70%-80% of the complete specimens' elastic modulus, appears at 90° of joint inclination. The joint inclination is the major influencing factor on the unified peak strength and the unified elastic modulus of the rock-like specimens containing many joints. Further analysis on the test results demonstrates that the transformation law of the relationship between the joint density or joint inclination and the stress-strain curve, as well as the unified peak strength and the unified elastic modulus, is related to the failure process of the specimen. The failure mode of the specimen can be classified into three categories:tension failure, shear failure, and mixed failure.
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Key words:
- rock-like specimens /
- rockjoints /
- inclination angle /
- density /
- uniaxial compression /
- peak strength /
- elastic modulus /
- failure modes
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參考文獻
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