土石交界隧道爆破开挖数值分析
Numerical analysis of the blasting excavation of tunnels with soil-rock interfaces
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摘要: 运用FLAC3D对黑山隧道土石交界段爆破开挖时爆破振动对隧道稳定情况的影响进行了数值分析.采用球面爆破冲击波的方法对爆破开挖进行了数值模拟,根据数值模拟结果提出了安全装药量,最后就其在爆破控制中的应用进行了分析.研究表明隧道爆破开挖过程中,拱顶及两侧拱腰底部发生了明显的应力重分布现象,拱顶土体对爆破振动敏感,易于发生塑性破坏,中部土体也有部分破坏,但并不影响开挖.Abstract: The effect of blasting vibration on Heishan tunnel with soil-rock interfaces was numerically analyzed with FLAC3D when the tunnel was excavated by blasting excavation.In the analysis the blasting excavation was simulated by a method of spherical blast waves.According to the numerical result,the safe charge of explosives was proposed and its application was analyzed in the blasting control.It is indicated that that the stress is redistributed at the vault and the bottoms of the arch waist.Soil zones in the vault are sensitive to blasting vibration.Although plastic failure develops mainly in the vault of the tunnel and there are also some damages in the center soil connecting with rock,they do not affect the overall stability of the tunnel.