城市浅埋隧道爆破原理

城市隧道以浅埋居多,对于岩石隧道掘进当前以钻爆法为主.城区浅埋隧道爆破区别于普通的山岭隧道体现在三个方面.一是,浅埋隧道本身的围岩分布在Ⅳ～Ⅵ级,爆破对围岩的扰动大.二是,城区需要保护的房屋类型多、地下管线复杂.三是居民对爆破振动承受能力弱,常常出现“爆破扰民”与“民扰爆破”现象.该文以大连地铁的浅埋隧道爆破施工为背景,分析柱状装药爆破理论,减轻爆破对围岩的破坏；给出了更人性化的爆破振动速度控制指标,尤其对地下管线给定爆破振动控制指标.为实现爆破振动控制,综合利用孔内外毫秒微差延时爆破技术,并对爆破振动测试给出布点依据.所有这些对城市浅埋隧道爆破原理进行系统阐述,对未来城市轨道交通建设有指导意义.

Blasting Principle of the Urban Shallow Tunnels

Most of the urban tunnels are shallow buried,and currently the main method of tunneling the rock tunnel is drilling and blasting method.Blasting the shallow tunnel in the cities differs from that in the ordinary mountain tunnels in three aspects.First,the wall rock of the shallow tunnels distributes between level IV-VI,and the wall rock disturbance caused by the blasting is huge.Second,the many types houses are needed protecting in the cities,and the underground pipelines are complex.Last,urban residents have less tolerance of the blasting vibration,thus the phenomenon of＂the blasting disturbing the residents＂and＂the residents holding back the blasting＇are common in the cities.Based on the background of construction of Dalian Metro,this paper analyzes the column charge blasting theory to mitigate the damage of the wall rock.It also gives a more human control of blasting vibration velocity indicators,especially control of blasting vibration of underground pipelines.In order to realize the control of the blasting vibration,the inside and outside hole millisecond delay blasting technique is comprehensively utilized,and it also provides the references of the test arrangement for the blasting vibration. The paper systematically explains the blasting theory for urban shallow tunnels;it also has the guiding significance for the future urban rail transit construction.