特殊构造砖烟囱定向爆破拆除

介绍了定向控制爆破技术拆除一座烟囱、水塔的结合体,拟爆结构物地坪以上27 m处设置钢筋混凝土结构水箱,致使重心高于一般烟囱,其外壁采用ф12 mm钢筋网箍和60 mm厚混凝土进行加固。周边环境复杂,距高压配电房仅1.4 m,为避免地坪处+0.5 m烟道口对定向的影响,将爆破切口位置提高到+3.0 m处;为减小触地振动、防止倾倒过程中出现后座,采用梯形切口,爆破切口长度取其周长62%,爆破切口高度取1.4 m。为克服烟囱外壁加固层和圆拱墙体钻凿深度不准确的影响,同排相邻炮孔采用一深、一浅的布置方式,其炮眼深度差值2~3 cm,装药结构应用正、反向起爆综合技术。采用开挖减震沟、设置缓冲带控制爆破振动等措施,爆破效果理想,保证了邻近建筑物及设施安全。

Directional Explosive Demolition of Special Brick Chimney

The directional blasting is used to demolish a combination of chimney and water tower.The reinforced concrete water tank at 27 m high makes the gravity center of chimney higher than ordinary chimney.The outer wall is strengthened by 12 mm steel bar hoop and 60 mm thick concrete reinforcement.The surrounding is complicated,which is only 1.4 m away from the high-voltage distribution room.In order to avoid the influence of the flue hole at +0.5 m on the orientation,the blast cut location is enhanced to +3.0 m level.The trapezoidal cut,whose length is 62% of its circumference and the height is 1.4 m,is used to reduce the touchdown vibration and the back movement during the process of the dumpling.The layout of one deep by one shallow hole with 2~3 cm difference,with combining the top initiation and end initiation,was chosen to overcome the influence of outer reinforcement layer and the inaccurate of the drilling in the arch wall.The approach of vibration damping ditch and the buffer zone was adopt with other method,such as elaborate design and construction,which keeps the blasting effect well and the adjacent buildings safe enough.