Abstract:

The vibration reduction mechanism of multilevel wedge cutting used in Yananlu Station side crossing Building No. 166 on Line No. 2 of Qingdao Metro is studied; the blasting parameters, i.e. row spacing, depth, angle, number, and charge volume of wedge cutting and arrangement of detonator are analyzed and tested, so as to minimize the influence of blasting on the existing buildings on ground surface. The results show that: 1) The Level 2 cutting and Level 3 cutting are the keys. 2) The spacing among blasting holes should not be larger than 350 mm and the row spacing should not be larger than 400 mm. 3) The depth of Level 3 cutting should be the largest. 4) The amount of Level 2 cutting should larger than 5 pairs; the amount of Level 3 cutting should larger than 4 pairs. 5) The Level 2 cutting and Level 3 cutting should be detonated hole by hole. The analytical results can effectively control the blasting vibration.

Key words: Qingdao Metro, mined Metro station, wedge cutting, blasting vibration, blasting parameters, micro vibration