基于气泡帷幕的大连湾海底隧道水下炸礁消压分析研究

Research on pressure dissipation of underwater reef blasting for Dalian Bay Subsea Tunnel based on bubble curtain method

大连湾海底隧道采用水下钻孔炸礁爆破的方式进行基槽开挖工作,爆破冲击波将对临近沉管隧道结构的安全稳定性产生极大的负面影响。依托大连湾海底隧道工程,采用气泡帷幕法开展爆破冲击波消压试验,基于监测数据分析气泡帷幕对水下爆破冲击波的消压效果,为实际爆破施工方案设计提供参考。结果表明:在30 m水深,20 cm间距,2 mm直径单排气孔,空压机工作压力1.62 MPa条件下,气泡帷幕能够大幅降低水下爆破冲击波峰值压力,消压系数达69.3%。

The foundation trench for Dalian Bay Subsea Tunnel is to be excavated by underwater borehole reef blasting and the shock wave by blasting would have a great negative impact on the safety and stability of the adjacent immersed tunnel structure.In this study, the bubble curtain method was used to conduct blasting shock wave depressurization test based on the Dalian Bay Subsea Tunnel project, and the effect of bubble curtain on depressurization of underwater blasting shock wave was analyzed based on the monitored data to provide reference for blasting designs. The results show that, with a water depth of 30 m, singlerow arranged jet-nozzles of 2 mm diameter at spacing of 20 cm, and at a 1.62 MPa working pressure of air compressors, the bubble curtain can significantly reduce the peak pressure of underwater blasting shock wave, and the pressure dissipation coefficient reaches 69.3%.