Abstract:

The vibration velocity of ground surface is monitored during blasting construction of TBM launching adit on right line of Yan′anlu Station on Qingdao Metro Line No. 2 adjacent to buildings; the site coefficient and the attenuation coefficient of different blasting zones of adit top heading are regressed; and the influence of free surface and minimum resistance line on blasting vibration are obtained, according to which the original blasting parameters are optimized. Finally, remarkable economic and technical benefits have been achieved. The results show that: 1) The blasting vibration is affected by free surface and the minimum resistance line. 2) The site coefficient and the attenuation coefficient of the different blasting zones of top heading are different; and those of cutting zones are the largest.

Key words: metro tunnel, wedge cutting, blasting vibration, free surface, minimum resistance line, blasting parameters