爆破振动对相邻隧道的影响性分析及控爆措施

Effect analysis and controlled measures research about blasting vibration to neighboring tunnel

通过大量二维和三维数值模拟计算,同时,结合紫坪铺隧道小净距段现场实测爆破振动数据,分析了小净距隧道爆破施工中后行隧道爆破对先行隧道的影响因素。研究了不同岩墙加固措施、不同施工方案及不同支护体系等情况下,小净距隧道中后行隧道爆破开挖对先行隧道的影响。得出先行隧道迎爆侧及开挖掌子面前后1B范围是影响较大部位,应加强监控量测的结论。提出了岩墙加固宜采用注浆加固、先行隧道初期支护宜及时封闭、掏槽眼宜远离中岩墙以及开挖进尺不宜大于净距的1/3等小净距隧道爆破施工的控爆措施。

According to a large amount of two-dimensional and three-dimensional numerical simulation, together with the observational blasting vibrant data about small clear distance of ZhiPingPu tunnel, the influencing factor applied to the precedence tunnel by the later one during blast construction of small distance tunnels was analysed. Also, the influencing factor applied to the precedence tunnel by the later one during blast excavation of small distance tunnels based on different consolidating measure of rock wall and different construction scheme was studied. A conclusion was reached that the side facing blast and the 1B area in tunnel face of the precedence tunnel are the greater affecting location and the monitoring and gauging should be strengthened. Based on analysis,some suggestions about controlling blasting measures were presented that the rock wall should be consolidated by the way of slip-casting, primary supporting of the precedence tunnel should be sealed in time, cut hole should be set far away from the middle rock wall, and excavation footage shouldn＇t be greater than one-third of the clear distance.