烟囱折叠拆除爆破切口高程与起爆时差优化模拟

针对烟囱折叠爆破拆除的两个最重要的因素,上部切口高程和上、下切口起爆时差优化配置才能保障工程安全、可控的情况。利用Ansys/LS-dyna非线性有限元软件首先模拟了50m高烟囱在上部切口20m高程时,0.1、1.0、2.0s的起爆时差对烟囱倒塌过程和倒塌后爆堆范围的影响;然后模拟上部切口10、15、20m高程的烟囱双向折叠爆破,在0.1、1.0、2.0s起爆时差方案下,得到不同切口高程的爆堆范围,最后比较了4种高程的爆破效果及爆堆范围。上部切口位于15m处时,烟囱倒塌过程更为合理,爆堆范围也比较接近参考范围。通过模拟和分析表明,对于50m高烟囱体双向折叠爆破拆除,上部切口高程和上、下切口起爆时差是决定爆破效果好坏的两个关键控制点,上切口高程为20m处时,随着起爆时差的增大,爆堆范围也增大。上部切口位置的选取使上部筒体质量占烟囱总质量的59.4%左右时,更有利于保障工程的安全性和倒塌过程、爆堆范围的可控性。

The optimization simulation of notch elevation and initiation time difference of the chimney demolition by folding blasting

In view of the two most important factors in the collapse of the chimney,the upper notch elevation and the optimal setting of the upper and lower notch initiation times could ensure the safety and control of the project.The initiation time difference influence of 0.1,1.0,2.0 s on the chimney collapse process and the blasting muckpile was simulated by using the Ansys/LS-dyna nonlinear finite element software at the upper notch 20 m height of the 50 m height chimney,and the upper notch 10,15,20 m height of the chimney bidirectional folding blasting,0.1,1.0,2.0 s initiation time difference program,and blasting muckpile of different notch elevation was got,finally,the blasting effect and the explosion range of the four kinds of elevation were compared,when the upper notch was located at 15 m,the chimney collapse process was more reasonable and the blasting muckpile also close to the reference range.It was shown that for the 50 m high chimney bidirectional folding blasting,the upper notch elevation and the initiation time difference were the two key control points that determine the blasting effect.When the incision elevation was 20 m,the time difference increased and the blasting muckpile was also increased.The selection of the upper notch position made the upper quality for about 59.4% of the total quality of the chimney,which was more conducive to the safety and collapse of the project and the controllability of the blasting muckpile.