青岛地铁隧道爆破开挖振动控制研究

Research on Blasting Vibration Control of Tunnel Excavation of Qingdao Subway

研究目的:以青岛地铁3号线试验段工程为背景,通过对隧道掘进向地表振动速度检测试验,得到浅埋隧道开挖爆破不同作用类型炮孔引起的地表振动特性及其衰减规律,并在不降低循环进尺的前提下,提出有效的降振措施。研究结论:开挖掌子面上不同的炮孔爆破类型其衰减规律有所不同,随着爆破起爆段别的增加,衰减公式中的K值逐渐递减,α基本保持不变;根据K、α值的变化规律和影响因素,采取了增加中心孔优化掏槽方案、调整起爆顺序、减轻爆破夹制作用的措施,爆破振动降低到1.5 cm/s以下。

Research purposes：Taking the experiment section of Line 3 of Qingdao subway project as the background,the test of the surface vibration vector resultant velocity caused by tunnelling was done to know the surface vibration characteristics and attenuation law induced by different types of hole when tunnelling and blasting the shallow tunnel,and the measures were offered for reducing the vibration on the premise of no cutting the tunnelling footage. Research conclusions：The attenuation law relied on the blasting type for excavating the working face.With the number of blasting initiation section increasing,the K value of the attenuation formula decreased gradually;and the α value basically remained unchanged.According to the variation law and influence factors of K and α values,the additional measures were taken,such asundermining the central hole,improving the initiation blasting order and reducing the folder effect of blast,to reduce the velocity of blasting vibration to below 1.5 cm/s.