大直径中空孔直眼掏槽微振动爆破参数研究

为最大限度减小掏槽区的爆破振动对地表建筑物的扰动,以青岛地铁3号线太延区间下穿伊美尔整形医院段为背景,通过理论分析和现场试验,对大直径中空孔直眼掏槽的中空孔孔径、掏槽装药炮孔数目、首响孔与中空孔距离、逐孔起爆时差和中空孔布设位置各爆破参数进行探讨。结果表明:在断面中下部位布置直径为120~150 mm的中空孔,环形布置4个掏槽眼,首响孔距中空孔200~350 mm,逐孔起爆时差宜在40 ms以上,可使掏槽爆破振速得到有效控制。

Study on Micro-vibration Blasting Parameters of Large-diameter Empty-hole Parallel Cut

The running tunnel from Taipingjiao Park Station to Yan’an Road Station of No. 3 Line of Qingdao Metro crosses underneath a plastic surgery hospital. In the paper, the blasting parameters under the condition of large diameter empty hole parallel cut, including empty hole diameter, blasting hole number, the space between the first blasting hole and the empty hole, the detonating delay time and the position of the empty hole, are discussed on basis of theoretical analysis and field test, so as to minimize the influence of the blasting on the existing surface buildings. The results show that the empty hole diameter should be 120~150 mm, 4 blasting holes should be drilled around the empty hole, the distance between the first blasting hole and the empty hole should be 200~350 mm, and the detonating delay time should be longer than 40 ms.