青岛胶州湾海底隧道陆域段近距下穿地表建筑物爆破震动控制技术

青岛胶州湾海底隧道陆域段钻爆施工期间,为确保距隧道拱顶约12 m的地表建筑物安全及隧道大断面掘进,通过采用下导超前、后续大断面扩挖施工方法,运用液压凿岩台车进行大中空孔直眼掏槽及合理化的钻爆设计等技术,将地表建筑物最大垂直震速控制在国标允许范围之内;通过采用孔外中段别雷管接力起爆,实现了大断面（超前下导、后续扩挖面）一次性点火起爆,解决了大断面一次性爆破雷管段别不足的难题;通过爆破震动测试及数据回归分析,得到了震动波在地层中的传播规律,并通过该规律进行药量真正校核。

Blasting Vibration Control Technology for Tunneling Underneath Surface Buildings with Shallow Cover: Case Study on Jiaozhou Bay Undersea Tunnel in Qingdao

In the drill and blast construction of the onshore section of Jiaozhou Bay Subsea Tunnel in Qingdao,there are surface buildings only 12 m above the tunnel crown.The technology of bottom heading followed by cross-section enlarging is adopted and large parallel cut made by hydraulic rock drilling jumbo and rational drilling and blasting design are used,which brings the maximum vertical vibration velocity of the surface buildings to be within the range allowed by the national standards.Sequence detonation by means of medium-delay detonators outside the blast hole is used,which achieves once ignition for the bottom heading and the subsequent cross-section enlarging and overcomes the difficulty in the insufficiency of the delays in once large cross-section blasting.Blasting vibration tests and regression analysis are made,which achieves the rules of the transmission of the vibration waves in the ground;the charging quantity is calibrated on basis of the wave transmission rules.