【摘要】 根据单轴卸载试验,获得岩样相应的应力应变曲线和轴向应变-径向应变曲线,并得到不同程度的损伤岩样。与完整的峰前曲线相比较,推断不同损伤程度岩样的卸载点所处于的应力应变曲线的阶段。将损伤岩样和破坏形成的岩块浇注在混凝土中,通过剪切试验获得岩石的抗剪强度。剪切试验结果显示,在裂纹稳定发展阶段卸载,岩样的抗剪强度下降很小,可能强度的变化掩藏在个体差异中;在裂纹不稳定发展阶段卸载,岩样的抗剪强度明显下降,特别是卸载点靠近强度峰值时;单轴压缩破坏形成的岩块仍具有相当可观的材料强度。更多还原

【Abstract】 Based on uniaxial unloading tests,stress-strain curves of rock specimens were acquired as well as their axial strain-lateral strain curves.Meanwhile,the rock specimens damaged in different degrees were obtained.By comparing with the complete curves before the strength peak,the segments of the stress-strain curves that correspond to unloading points of the rock specimens damaged in different degrees were determined.The damaged rock specimens and the broken rock were poured in concrete,and shear test on the concreted rock samples was made to acquire their shear strength.The results of test showed that if rock was unloaded in the stage of fracture stably propagating the shear strength of damaged rock slightly decreased,the change of strength might be concealed by individual difference of rock,but if rock was unloaded in the stage of fracture unstably propagating,especially was unloaded when the strength was close to the peak,the shear strength obviously decreased.The bocks formed in uniaxial compression failure still had considerable strength.更多还原