HJC模型参数确定及隧道光面爆破炮孔间距优化

Determination of HJC Model Parameters and Optimization of Tunnel Smooth Blasting Hole Spacing

为了提高光面爆破的质量,减少围岩的超欠挖,通过数值模拟研究了炮孔间距的优化方法。基于现场设计参数,建立不同炮孔间距的有限元模型,得到了最佳的炮孔间距,最后将数值模拟的结果在玉皇山隧道工程上进行了验证。结果表明:随着炮孔间距的增大,炮孔之间的拉应力逐渐降低,裂纹的贯通程度逐渐降低,即当炮孔间距小于85cm时,炮孔之间的损伤可以有效贯通,大于85cm时,两孔之间的未能形成有效的贯通。孔间有效应力在100μs左右到达峰值,有效应力峰值随炮孔间距的增大逐渐降低。得到最佳的炮孔间距85cm左右,并在玉皇山隧道进行了验证,取得了较好的效果。

In order to improve the quality of smooth blasting and reduce over excavation and under excavation of surrounding rock,an optimization method for borehole spacing was studied through numerical simulation.Based on on-site design parameters,finite element models with different borehole spacing were established,and the optimal borehole spacing was obtained.Finally,the numerical simulation results were validated in the Yuhuangshan Tunnel project.The results show that as the spacing between the boreholes increases,the tensile stress between the boreholes gradually decreases,and the degree of crack penetration gradually decreases.That is,when the spacing between the boreholes is less than 85cm,the gradual damage to the boreholes can be effectively penetrated.When the spacing is greater than 85cm,effective penetration cannot be formed between the two boreholes.The effective stress between holes is 100μThe peak value is reached around s,and the effective stress peak gradually decreases with the increase of borehole spacing.The optimal borehole spacing of about 85cm was obtained and verified in the Yuhuangshan Tunnel,achieving good results.