分区分台阶深孔爆破技术在城市土石方开挖中的应用

城市中心爆破具有周边环境复杂,地下管线密集,安全风险系数高的特点,需采取特殊的爆破施工技术控制爆破有害效应。以汉阳人信汇A地块土石方控制爆破工程为背景,采用高效、安全的分区分台阶深孔爆破技术,在爆区距离被保护体20 m范围内的严格控制区域采用4 m的台阶,孔距2.8 m,排距2.5 m;在爆区距离被保护体20 m外的一般控制区域,采用8 m高的台阶,孔距3 m,排距2.8 m;施工过程中通过使用澳瑞卡高精度雷管、开挖减振沟和密目安全网覆盖等安全辅助措施,保证了周边构筑物及地下管网的安全,且大大提高了施工效率。

Application of Sub-step Deep-hole Controlled Blasting Technology in City Earthwork Engineering

The urban blasting has the characteristics of complex surrounding environment,dense underground pipeline and high safety risk.It is necessary to adopt special blasting construction technology to control the harmful effect of blasting.Based on the controlled blasting project of earthwork in the Ren Xinhui A block of Hanyang,the sub-step and deep-hole controlled blasting technology is applied as a high-efficient and safe control technology.In the project,the bench height 4 m,hole spacing 2.8 m and row spacing 2.5 m are adopted in the strictly controlled area less than 20 m near to the protected area.In the general control area with 20 m away from the protected body,the bench height 8 m,hole spacing 3 m and row spacing 2.8 m are adopted.In the construction process,Orica high-pre-cision detonators,excavating vibration reduction trenches,laying dense mesh safety nets are used to ensure the safety of peripheral structures and underground pipe networks.