小高宽比多跨承重立柱楼房定向爆破拆除

Directional Blasting Demolition of Multi-span Load-bearing Column Building with Small Height-width Ratio

针对待拆除楼房结构上高宽比接近1的特点,以及属于违建楼房和所处环境比较复杂(不允许有后座发生)的情况,选择向西定向倒塌的爆破拆除方案。为使待拆建筑物无后座顺利倒塌且解体充分,在待拆楼房1~3层设计爆破切口,并通过试爆,确定出各不同截面承重立柱的合理爆破参数。同时对爆破前对建筑物的非承重结构——楼梯间进行必要的预拆除。采用长延时起爆等技术,确保待拆楼房的倒塌方向和坍塌解体效果。对楼内爆破立柱进行安全防护、外围搭设安全防护屏障等措施,有效地控制了爆破飞散物及落地飞溅的危害。三角形切口、降低局部强度、长延时起爆技术和开挖减震沟、铺设缓冲层等防振措施有效地降低了爆破振动和落地振动对周围建筑物的影响,最终取得了理想的爆破效果。

Considering that the height-width ratio of the illegal building to be demolished is close to 1,and the environment is complex(no recoil is allowed),a blasting demolition plan of directional collapse to the west is selected.In order to make the building to be demolished collapse smoothly and fully disintegrate without recoil,the blasting cuts are designed on the 1st~3rd floors,and the reasonable blasting parameters of the bearing columns with different sections are determined by a trial blasting.At the same time,the staircases which are the non-bearing structure of the building are demolished before blasting.A long delay initiation technology is used to ensure the collapse direction and collapse effect of the building to be demolished.The blasting columns in the building are protected and the safety protective barriers are set up in the periphery to effectively control the hazards of blasting flying objects and falling splashing.The anti-vibration measures,such as adopting triangular incision,reducing local strength,using long delay initiation technology,excavating damping ditch and laying buffer layer,can effectively reduce the impact of blasting vibration and ground vibration on the surrounding buildings,and finally ideal blasting effect is achieved.