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基于在伺服试验机上获得的不同围压下断续预制裂隙大理岩体积应变-轴向应变全程曲线,分析了围压对断续预制裂隙大理岩扩容特性的影响规律。结果表明,完整和断续预制裂隙大理岩裂纹损伤阈值随着围压的增加均近似呈线性增大,而且裂纹损伤阈值对围压的敏感性低于峰值强度;同等围压下,粒径较小的中晶大理岩具有较高的裂纹损伤阈值;完整或断续预制裂隙大理岩的长期内摩擦角均显著低于瞬时内摩擦角值,但长期黏聚力的降低幅度与裂隙分布密切相关;完整或断续预制裂隙大理岩的峰值强度越高,相应的裂纹损伤阈值也越大,且两者之间具有较好的线性关系。研究结论对于岩石工程设计和数值分析时断续节理裂隙岩体力学参数选取具有一定的参考价值。
Based on the curves of volumetric strain and axial strain of intermittent prefabricated fractured marble under different confining pressures obtained on a servo testing machine, the effect of confining pressure on the dilatancy behavior of intermittent prefabricated fractured marble was analyzed. The results show that the damage thresholds of marble cracks in intact and intermittent prefabricated fractures increase linearly with the increase of confining pressure, and the sensitivity of crack damage threshold to confining pressure is lower than the peak intensity. Under the same confining pressure, Small medium-sized marble has a higher crack damage threshold. The long-term internal friction angle of intact or intermittently pre-fractured marble is significantly lower than the instantaneous internal friction angle, but the reduction of long-term cohesion is closely related to the fracture distribution The higher the peak intensity of intact or intermittent prefabricated fractured marble is, the larger the damage threshold is and the better the linear relationship is. The conclusion of the study is of certain reference value for rock mechanics parameters selection of fractured rock mass in rock engineering design and numerical analysis.