兰青复线虎头崖隧道微振动爆破技术实践

Research onVibration Blasting Technology in Construction of Lanqing Double line Hutouya Tunnel

新建兰青复线虎头崖隧道出口段与既有隧道线间距较近,为保证既有隧道正常行车安全,对新建和既有隧道进行支护加固并采用微振动爆破技术施工,同时采用振动测试仪对隧道爆破振动进行监测,根据监测结果对下一次爆破参数进行优化。通过合理选择爆破时差、最大装药量、微差起爆、掘进进尺、预裂爆破等方面的振动控制技术措施,使该隧道开挖施工爆破中的地面振动速度值控制在安全范围以内,保证了虎头崖隧道开挖作业安全、顺利地进行。

The exit section of the new constructed Lanqing double line Hu-Tou-Yan tunnel is too close to the old tunnel. To ensure the traffic safety of the old tunnel, the vibration blasting technology is adopted in the construction of reinforcing both new and the old tunnel, at the same time, the vibration tester is used to monitor the blast vibration of the tunnel, so the subsequent blasting parameter can be optimized on the basis of monitoring result, moreover, through choosing technologies such as blasting time difference, maximum charge quantity, millisecond blasting, excavation span and springing blasting rationally, the ground vibration velocity is controlled in safety margin during the process of the tunnel excavation construction, consequently the safety and the process are ensured in the construction of old tunnel.