为减小爆破振动速度和提高炮眼利用率，以青岛地铁2号线车站主体Ⅰ部上台阶的爆破开挖为背景，从理论上分析了由于掏槽区域爆破效果差引起爆破振动过大，由于掏槽眼不对称、掏槽区域布置不当、掏槽眼间排距过大、辅助眼排距过大、未封堵炮孔等原因造成炮眼利用率较低。结合理论计算和工程前期施工经验对楔形掏槽参数进行了优化，同时在校核单段最大起爆药量时考虑了多自由面的影响。结果表明： 优化后的复式楔形掏槽使炮眼利用率提高到90.5%，爆破振动速度控制在0.7 cm/s以内。

The utilization rate of blasting holes is usually influenced by asymmetry of cutting holes, irrational layout of cut zone, large spacing among cut holes, large spacing among assistant holes and nonstemming of the blasting holes. In order to improve the utilization rate of blasting holes and minimize the blasting vibration velocity, some factors are analyzed based on the blasting excavation of Zone 1 of top heading of Metro station on No. 2 Line in Qingdao. In this paper, the parameters of wedgeshaped cut are optimized by means of theoretical calculation and construction experience. In addition, multiple free surface is taken into consideration to check the maximum individual ignition explosive quantity. The results show that the utilization rate of blasting holes was improved to 90.5%, and the blasting vibration velocity was limited within 0.7 cm/s by the compound wedgeshaped cut used.