城市硬岩隧道下穿砖木结构建筑爆破控制技术

Blasting Control Techniques for an Urban Hard-Rock Tunnel Passing Under Brick-Wood Buildings

青岛地铁一期工程3号线03标段区间隧道下穿济军第一疗养院口腔科医院,隧道埋深14m。为了将爆破震动的影响程度降低到最小,开挖过程中采用了大直径中空直眼掏槽、控制单段最大起爆药量的方法,将地表震动速度控制在1.5cm/s以内,确保了地面建筑物、附近交通干道的安全;同时应用孔外延期技术对爆破网路进行优化设计,减少了因雷管段别限制而增加的爆破次数,降低了爆破所需时间,取得了良好的经济与社会效益。

A running tunnel of lot 3 of the Qingdao metro line 3 passed under a dental hospital of the First Sanitarium of the Jinan Military Region at a depth of 14m. To minimize the impact from blasting vibrations, large diameter hollow-cylinder cutting and controlled maximum priming charge per delay were used as countermeasures in the excavation. In this way, the vibration velocity of the ground surface was controlled within 1.5cm/s and the safety of the ground buildings and main roads nearby was guaranteed. Meanwhile, using the outer-hole delaying technique, the optimized blasting network reduced the blasting times induced by the detonator segments and shortened the blasting duration, resulting in social and economic benefits.