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基于细观损伤力学和动力有限元方法,模拟分析了节理岩体在刀具动态荷载作用下的损伤破裂过程,探讨了节理间距和节理角度的影响。在动力分析模型中,通过考虑黏弹性边界以排除边界应力波反射的影响,提高了计算精度。数值模拟结果表明,节理的存在改变了岩体中应力波的传播模式。一方面,节理面反射的拉伸应力波加剧了节理与刀具间岩体的碎裂;另一方面,软弱节理面破坏吸收了应力波能量,阻碍了应力波向下的传播,减弱了下部岩体的破坏程度。模拟结果还表明,节理间距越小,岩体破坏程度更加明显。倾斜节理的存在使刀具下部的裂纹出现不对称性扩展特征,影响了主裂纹向下扩展的能力,限制了其伸展的空间。节理岩体在刀具动态作用下的破坏过程研究还很少见到,研究结果对于节理岩体动态破坏的机理以及地下工程开挖等实际应用,具有一定的参考价值。
Based on meso-damage mechanics and dynamic finite element method, the damage and fracture process of jointed rock mass under the dynamic load of tool is simulated and analyzed, and the influence of joint spacing and joint angle is discussed. In the dynamic analysis model, the calculation precision is improved by considering the viscoelastic boundary to exclude the influence of boundary stress wave reflection. Numerical simulation results show that the existence of joints changes the propagation mode of stress wave in rock mass. On the one hand, the tensile stress wave reflected by the joint surface aggravates the fragmentation of the rock mass between the joint and the tool. On the other hand, the failure of the weak jointed surface absorbs the energy of the stress wave, impedes the downward propagation of the stress wave and weakens the lower rock Body destruction. The simulation results also show that the smaller the joint spacing, the more obvious the damage of rock mass. The existence of oblique joints causes the crack at the lower part of the tool to exhibit the asymmetric spreading feature, which affects the ability of the main crack to expand downward and limits the space for its extension. The research on the failure process of jointed rock mass under the dynamic action of cutter is seldom seen. The research results have certain reference value for the practical application of dynamic failure mechanism of jointed rock mass and excavation of underground engineering.