层状板岩单轴压缩试验及数值研究

Experimental and numerical investigation on uniaxial compression test of layered slate

为研究层理结构面对岩体力学性能的影响,以陕西木寨岭隧道层状炭质板岩为研究对象,对层状板岩在单轴压缩作用下的力学性能进行试验及数值分析。在数值模拟中,使用离散元框架MUSEN即固体键合颗粒模型(BPM)模拟层状岩体在准静态压缩过程中的破坏行为。研究结果表明:1)微观弹性模量与宏观弹性模量大致呈线性关系,通过插值计算,可将试样弹性模量映射为微观模量进行数值模拟计算。2)随着轴向与切向强度增加,对应的峰值荷载及位移随之增加。3)在相同参数及边界条件下,根据随机性原理,形成多种不同颗粒分布模型,最终的荷载−位移曲线表明模型对其力学响应影响较小。4)试验中,当层理倾角为0°及90°时,峰值荷载较大;当层理倾角分别为30°,45°及60°时,峰值荷载较接近,即随着倾角的逐渐增加,大致呈“U”型分布。5)在破坏形态上,不同层理倾角下大致呈现劈裂拉伸破坏、剪切滑移破坏以及复合型拉剪破坏。6)在相同模型下,通过程序编制构建不同层理的模型,模拟结果的力学响应及破坏形态对比试验具有良好的一致性,再现了不同层理倾角层状板岩的劈裂演化过程。

In order to investigate the effect of bedding structure on the mechanical properties of rock masses,the layered carbonaceous slate of the Muzhailing Tunnel in Shaanxi was taken as the research object,and experimental and numerical analysis were conducted on the mechanical properties of the layered slate in the uniaxial compression test.The discrete element framework MUSEN,which is also called bonded particle model(BPM),was used to simulate the failure behavior of layered rock mass in the quasi-static compression process.The results show that:1)The microscopic elastic modulus and the macroscopic elastic modulus are roughly linear.Through interpolation calculation,the elastic modulus of the test can be mapped to the microscopic modulus for numerical simulation calculation.2)As the axial and tangential stiffness increases,the load and displacement corresponding to the peak value increase.3)Under the same parameters and boundary conditions,according to the principle of randomness,a variety of different particle distribution models are formed.The final load-displacement curve shows that the model has little effect on its mechanical response.4)In the test,when the bedding angle is 0°and 90°,the peak load is larger;when the bedding angle is 30°,45°and 60°,the peak load is closer,which means that with the gradual increase of the inclination angle,it is roughly U-shaped distributed.5)In terms of failure morphology,splitting tensile failure,shear-slip failure and composite tensile-shear failure are generally present at different bedding inclination angles.The failure modes can be summarized as straight,broken and curved failure.6)With the same model,different bedding models are constructed through programming.The mechanical response of the simulation results and the comparison test of the failure form have good consistency,and the split evolution of the layered slate at different bedding angles is reproduced.