新建双洞TBM隧道与既有钻爆法隧道近接分区研究

Research on Adjacent Partition of Newly-built Double-hole TBM Tunnel and Existing Drilling and Blasting Method Tunnel

依托重庆轨道交通5号线歇台子—石桥铺区间双洞TBM隧道,采用FLAC 3D软件模拟TBM隧道施工,运用摩尔-库伦准则,综合考虑围岩塑性区分布、隧道间夹土层应力变化,分析了双洞TBM隧道与既有钻爆法隧道的近接分区。结果表明:TBM隧道先行洞对钻爆法隧道的影响范围约为钻爆法隧道等效直径的1.5倍;TBM隧道后行洞对钻爆法隧道的影响范围约为钻爆法隧道等效直径的1.0倍。据此,对新建隧道近接影响区域设计与施工时可采取增强配筋20%、回填灌浆、超前注浆等措施来保证施工安全。

Based on double-hole TBM tunnel in Xietaizi-Shiqiaopu section of Chongqing Rail Transit Line No. 5,TBM tunnel construction was simulated by using FLAC 3 D software and applying Mohr-Coulomb criterion,the adjacent partition of the double-hole TBM tunnel and the existing drilling and blasting method tunnel was analyzed in comprehensive consideration of the distribution of the surrounding rock plastic zone and the stress change of the intercalated soil layer between the tunnels.The results show that the influence range of TBM advanced driving tunnel on the drilling and blasting method tunnel is about 1. 5 times the equivalent diameter of the drilling and blasting method tunnel,and the influence range of TBM subsequent driving tunnel on the drilling and blasting method tunnel is 1.0 times the equivalent diameter of the drilling and blasting method tunnel.Accordingly,the measures including strengthening reinforcement of 20%,backfilling grouting and advance grouting could be taken to guarantee the construction safety in the adjacent influence area design and construction of the newly-built tunnel.