切口形式对烟囱爆破拆除影响的数值模拟

Numerical Simulation on the Influence of Notch Opening for Chimney Demolition Blasting

爆堆范围、倒塌历时和倒塌过程中的速度是衡量烟囱拆除爆破工程质量的重要指标。采用数值模拟筒形烟囱拆除爆破的过程,重点探讨其在不同切口形式下的爆堆范围、倒塌时间和速度时程曲线。通过此特定研究情况下的模拟得知:正梯形和矩形切口有小范围后坐,倒梯形切口会前冲,致使爆堆较大;矩形切口闭合最快,但顶端着地延缓,正梯形切口和倒梯形切口闭合时间和顶端着地时间较为接近;矩形切口顶端着地速度最大,倒梯形切口次之,正梯形切口最小。

The muckpile range,the collapsing duration,and the collapsing velocity are very important indexes for chimney demolition blasting.The change curves of the muckpile range,the collapsing duration,and the collapsing velocity under different types of openings were discussed on the numerical simulation for the process of a cylindrical chimney demolition blasting.Through the special simulation,it can be obtained that the isosceles trapezoid and rectangular openings led to small backblow,and the inverted trapezoid opening would lead to rush forward and form a larger range of muckpile.During the demolition blasting,the rectangular opening showed the shortest closing time,but the longest landing time.Closing time and top landing time of isosceles trapezoid opening and inverted trapezoid opening were near same.The top landing speed of rectangular opening was the fastest,the inverted trapezoid opening followed,and the isosceles trapezoid opening＇s slowest.