复杂环境下110 m冷却塔控制爆破拆除

Blasting Demolition of 110 m Cooling Tower in Complex Environment

介绍了一座高110 m的薄壁钢筋混凝土冷却塔的定向控制爆破拆除。针对冷却塔高度大、塔壁薄以及底部直径大的特点,采用“开窗口、断钢筋、预留支撑板块”爆破方案,预拆除中通过对冷却塔爆破缺口进行优化设计,在爆破边沿开设2个简化的定向窗。在爆破区域仅对冷却塔人字柱底部和顶部进行布孔爆破,将爆破切口分为5个起爆区域采用分区分段的非电毫秒延期起爆技术。为了有效控制爆破危害效应,在冷却塔倒塌方向铺设缓冲土层及钢板进行双重防护有效地降低了塌落冲击振动,在爆破切口处采用密目网和土工格栅覆盖相结合的防护措施有效地控制了飞石,未对周围建(构)筑物造成损害。爆破效果表明:在爆破切口边沿开设2个简化的定向窗窗口,不仅减少了钻孔及相关工作量,降低了安全隐患和防护难度,而且提高了预处理部分的结构稳定性,防止爆破切口处下坐;通过对定向窗的简化设计,使得冷却塔在倾倒过程中发生扭曲充分解体,爆堆较为集中,触地振动较小,爆破效果良好。

A 110 m thin wall reinforced concrete cooling tower has been demolished by controlled blasting.Aiming at the characteristics of large height,thin wall and large bottom diameter of the cooling tower,the blasting scheme of“opening window,breaking steel bar and reserving supporting plate”was adopted.In the pre-demolition process,two simplified directional windows were set up along the edge of the blasting zone by optimizing the blasting incision of the cooling tower.In the blasting area,only the bottom and top of the herringbone column of the cooling tower were blasted,and the blasting incision was divided into 5 blasting areas using the non-electric millisecond delay initiation technology.In order to control the damage effect of blasting,laying buffer soil layer and steel plate in the collapse direction of the cooling tower for double protection effectively reduced the collapse touch vibration.The protective measures combined with mesh and geogrid covering at the blasting incision effectively controlled the flying stones without causing damage to the surrounding structures.The blasting effect shows that setting two simplified directional windows on the edge of the blasting incision not only cuts down the drilling and related workload,reduces the safety hazard and the difficulty of protection,but also improves the structural stability of the pre-treatment part and prevents the blasting incision from falling.Through the simplified design of the directional window,the cooling tower distorts and disintegrates fully in the collapse process,with a concentrated explosion pile and small ground vibration.