隧道爆破减振孔减振效果研究

Research on vibration reduction effect of blasting shock-absorbing holes in tunnel

为探究不同减振孔布置方式对隧道爆破时减振效果的影响,采用ANSYS/LS-DYNA软件构建隧道爆破数值模型,从围岩振速、应力和损伤3个方面对比分析无减振孔、常规减振孔、加密减振孔和加大减振孔4种工况的减振效果。研究结果表明:加大减振孔孔径后,在振速和应力方面的减振效率相对较高,分别达到27.7%,27.9%;减振孔的设置可以有效阻碍爆破应力的传播和损伤裂纹的扩展,加大孔径的减振孔阻碍效果更好,使隧道爆破时的围岩应力辐射半径和损伤半径均减少约1/2,常规减振孔和加密减振孔的阻碍效果均相对较小。研究结果可为隧道钻爆法施工中进一步优化减振孔布置方式提供参考。

To explore the influence of different arrangement methods of shock-absorbing holes on the vibration reduction effect during tunnel blasting,the ANSYS/LS-DYNA software was used to construct a numerical model of tunnel blasting.The vibration reduction effect of four working conditions,including without shock-absorbing holes,conventional shock-absorbing holes,encrypted shock-absorbing holes,and enlarged shock-absorbing holes,was compared and analyzed from the change in surrounding rock vibration velocity,stress,and damage.The results show that after increasing the aperture of shock-absorbing hole,the vibration reduction efficiency in terms of vibration velocity and stress is relatively high,reaching 27.7%and 27.9%,respectively.The setting of shock-absorbing holes can effectively hinder the propagation of blasting stress and the expansion of damage cracks.The enlarged shock-absorbing holes have a better hindering effect,reducing the stress radiation radius and damage radius of the surrounding rock during tunnel blasting by half.The hindering effect of conventional and encrypted shock-absorbing holes is relatively small.The research results can provide a reference for optimizing the arrangement methods of shock-absorbing holes in the drilling and blasting construction of tunnels.