浅埋地铁隧道近距离下穿危旧建筑爆破振动风险控制技术

青岛地铁一期工程3号线03标段区间隧道下穿湛山路3号民房,隧道拱顶到3号民房基础最小距离为9.5m。开挖过程中采用大直径双中空孔直眼掏槽、孔内分段延期爆破、控制单段最大起爆药量的方法,将地表振动速度控制在1.0cm/s以内,确保了地面建筑的安全。同时对爆破现场连续监测5次、共计36炮次,在统计分析炮次与振速最大值之间的对应关系基础上,提出在爆破施工过程中应该注意克服人的安全意识＂疲劳＂期,才能确保下穿段全过程的不超振。

The Risk Control Technique of Blasting Vibration for Shallow Subway Tunnels Under-passing the Dilapidated Buildings Closely

The tunnel of the 03 Contracted Section of the 3rd Line of the 1st period project of Qingdao Metro has to under-pass a civilian house at No.3of Zhanshan Road,with the shortest distance between the arch top of the tunnel and the foundation of the civilian house being 9.5m.In the process of the excavation operation,in order to minimize the impact of the blasting vibration,the methods of the double large-diameter straight hole-cutting,section-by-section delay blasting inside the hole,controlling the maximum amount of explosive for each sectional blasting and limiting the surface vibration velocity to 1.0cm/s are used to ensure the security of the surface building.In the meantime,upon the basis of continuously monitoring the blasting site five times,totally,36 times of blasting are performed,the statistical analysis of the corresponding relations between the times of the blasting and the maximum value of the blasting velocity,it is pointed out that the＂fatigue period＂of the safety awareness of human beings should be paid attention to and overcome during the blasting construction.Only in this way can the extra-vibration in the course of the under-passing construction be fully avoided.