分区延时技术在砖混结构楼房爆破中的应用

Application of zone delay technology in blasting of brick-concrete structure building

砖混结构楼房爆破拆除通常出现预拆除危险性高,爆破振动、塌落振动和空气冲击波危害范围大等现象。基于一栋8层砖混楼房爆破拆除工程,在合理设计爆破切口、爆破参数及科学预拆除的同时,提出了排间、列间和层间分区三向延时起爆网路,并对危害效应进行了安全校核和制定安全防护措施。实践表明:楼房主体呈定向倒塌,由于起爆网路的作用,使得楼房向先起爆一侧偏离10°~15°;楼房为逐跨倒塌,大大降低了塌落振动;整个倒塌过程因剪切、弯折、扭曲、牵扯和挤压等力的作用,使得楼房解体效果良好,且散落距离短。整栋楼通过三向起爆网路大大减小了同段药量,有效控制了爆破振动、空气冲击波和噪声等危害影响。经过精心设计和精细施工,爆破效果达到了预期目的。

The blasting demolition of brick-concrete structure buildings usually has the characteristics of high pre-demolition risk,and the damage range of blasting vibration,landing vibration and air shock wave is relatively large.Based on the blasting demolition project of an eight-storey brick-concrete building,a three-dimensional delayed detonation network of row,rank and interlayer zoning was designed by rational design of directional blasting gap,blasting parameters and scientific pre-demolition.Safety calculations and safety precautions are also taken for blasting hazards.The practice shows that the main body of the building is directional collapse.Due to the function of the detonation network,the building deviates from the first blast side by 10°-15°.The building collapsed section by section,greatly reducing the collapse vibration.Due to the shearing,bending,twisting,pulling and squeezing forces,the entire collapse process has a good disintegration effect and a short stacking distance.The whole building has greatly reduced the same amount of dose through the Sub-regional three-way blasting network,effectively controlling the harmful effects such as blasting vibration,air shock wave and noise.Through careful design and fine construction,the blasting effect has achieved the intended purpose.