双轴加载下成组裂隙参数对类岩石试件力学性质的影响规律

Effect of Group Fissures Parameters on Mechanical Properties of Rock Specimens Under Biaxial Loading Conditions

煤矿深部地层岩巷围岩裂隙分布复杂,裂隙参数对岩体力学性能影响较大。为研究深部地层裂隙岩体在掘进扰动条件下的破坏规律与力学性能,制备不同裂隙倾角和长度的成组裂隙类岩石试件,开展模拟煤矿深部巷道掘进扰动的双轴加载试验,研究类岩石试件力学特性及其影响因素。研究结果表明:成组裂隙试件强度受预制裂隙的倾角影响明显,当预制裂隙倾角为30°~45°时,试件的起裂应力和峰值应力为最小值,当裂隙倾角为90°时,试件的起裂应力和峰值应力最大。在双轴固定比例加载的条件下,裂隙倾角和长度均会对试件的强度产生影响,其中裂隙倾角对试件强度的影响最为明显,裂隙长度的影响较小。

The distribution of the surrounding rock fissure is complex in the deep stratum rock roadway of coal mine,and the fissure parameters have a significant impact on the mechanical properties of rock mass.In order to study the failure law and mechanical properties of fractured rock masses in deep strata under excavation disturbance conditions,a group of specimens containing pre-existing joints with different dip angles and lengths were prepared.A biaxial loading test was conducted to simulate the excavation disturbance of deep coal mine tunnels,and the mechanical characteristics and influencing factors of rock specimens were studied.The results show that the strength of the samples with group fissures is obviously affected by the dip angle of the pre-existing joint.When the dip angle of the pre-existing joint is 30°~45°,the crack initiation stress and peak stress of the specimens are the minimum,and when the dip angle is 90°,the crack initiation stress and peak stress of the specimens are the maximum.Under the condition of biaxial fixed proportion loading,the dip angle and length of the pre-existing joints have an impact on the strength of the specimen.Among them,the dip angle of the pre-existing joints has the most significant effect on the strength of the specimen,while the length has little effect.