考虑断层滑移应力波辐射特征的巷道支护参数优化研究

Optimization of tunnel support parameters with consideration of seismic wave radiation pattern in the fault-slip burst

随着地下矿山开采向深部逐渐延伸,断层滑移引起的岩爆事件日益增多且破坏性极大,已经成为威胁矿山安全的重要因素。通过建立三维离散元模型,基于平面应变问题,开展了三维模型平面应变等效计算与二维离散元模型对比分析,结果表明该研究模型在三维空间模拟地震波的传播是可行的。通过研究辐射特征对应力波传播的影响,揭示了P/S波传播过程的方向性并进行了验证,计算结果符合断层滑移的双力偶模型。在此基础上,通过与Kaiser等提出的设计尺度率公式进行对比,发现已有的设计尺度率公式并不能完全满足工程实际要求,利用三维离散元程序开展数值计算分析能够进一步优化支护参数,以此更好地服务矿山支护系统设计,确保地下矿山安全高效开采。

As the underground mining extends gradually towards depth,more and more seismic events induced by fault slip occur and cause great damages,which have become a severe potential threat to mining safety.In view of the plane strain problems,through the three dimensional discrete model established,comparison and analysis was carried out between the equivalent calculation of plane strain in 3D model and a 2D discrete model.The results have shown that the research model developed to simulate the propagation of seismic wave in 3D is feasible and applicable.The study of the effect of radiation pattern on seismic propagation revealed and tested the direction of P-and S-wave propagation,which presents high consistency to double couple model of the fault slip.On this basis,the comparison with the design scaling law formulas proposed by Kaiser and associates finds that the existing design scaling law does not totally satisfy the demand of practical engineering.Numerical calculation and analysis with the three dimensional discrete model can further optimize the support parameters,provide better service for system design of mining support,and ensure the safety and high efficiency in mining.