锦州电厂240m高钢筋混凝土烟囱爆破拆除

Explosive Demolition of 240 m-high Reinforced Concrete Chimney in Jinzhou Power Plant

在复杂环境下,锦州电厂240 m高钢筋混凝土烟囱采用地面以上+0^+5.0 m的爆破切口、复式正梯形切口形式定向倒塌控制爆破拆除。通过设计30°的切口初始闭合角,50°的切口复合闭合角,5 m的切口高度和217°的切口下沿水平切口圆心角,并在切口上沿开设小梯形定向窗的方法,烟囱取得良好的爆破效果,爆破危害控制较好。总结得出,超高型烟囱自重大,采用低位爆破切口爆破拆除时具有下坐量大,倒塌时间长,方向难以控制等特点。

In a complex environment,a 240 m-high reinforced concrete chimney was demolished by using directional controlled blasting,with compound trapezoid blasting cut.By setting up the initial closed angle at 30°,the composite closed angle at 50°,the original cut height 5 m,the central horizontal angle of the lower edge of the cut at 220°,and opening a small trapezoidal directional window along the upper edge of the cut,good blasting effect were achieved and the blasting damage was well controlled.The summary of the blasting results shows that,due to the large weight of ultra-type chimney,when demolishing scheme with low blasting cut was performed,the chimney would have a trend of sit down seriously,and a long collapse time and difficulty in controlling the direction would appear.