超小净距交叉隧道爆破与安全技术

Blasting Safety Technologies in the Circumstance of Cross Tunnels with Small Interval

介绍了采用下导坑领先再分三步全断面扩大的爆破开挖方法,通过现场监测,参考岩石破坏的最大峰值速度,对在空间上形成超小净距交叉隧道、平面上形成小净距平行隧道工程的爆破震动监测及控制爆破技术进行探讨,对爆破设计、炮眼水压爆破、单孔单响毫秒微差爆破起爆网路和爆破安全控制技术进行了分析和论述。并通过对既有隧道开展围岩稳定性、爆破振动监测和信息化施工的监测,根据各个测点测试的震动速度值和观察的实际情况,进一步验算爆破震动、调整爆破参数和网路,使爆破产生的质点振动速度控制在安全范围内,在确保既有隧道结构的安全和正常营运的同时使在建隧道顺利通过。

This paper introduces blasting based excavation method featured by access ramp as passage prior to overall 3-step cross section extending operation,discusses blasting vibration monitoring and blasting control technologies in construction of cross tunnels with small interval developed in the space and parallel tunnels with small interval on the plane based upon field monitoring data,considering ultimate peak rate of rock failure,and analyzes technologies in blasting design,hole hydraulic blasting,blasting network for single hole millisecond blasting once of each time and blasting safety control.Through monitoring on rock mass stability,blasting vibration and information oriented construction and based on the actual results of observations and vibration rate value tested at various measuring points,furtherly the blasting vibration is checked and blasting parameters and network is adjusted to control blasting specific peak particle velocity within safety limit,not only ensure the safety and normal operation of the existed tunnel structures,but also to safeguard the smooth passage of the constructing tunnel.