砖烟囱定向爆破拆除倾倒过程研究

RESEARCH ON BRICK CHIMNEY COLLAPSING PROCESS BY DIRECTIONAL BLASTING DEMOLITION

烟囱爆破拆除无论是拆除高度还是拆除的难度都在日益增大。本文运用力学原理建立砖烟囱倒塌的模型,采用数学方法推导了烟囱最大弯矩区域,进而对砖烟囱倒塌过程进行数值模拟研究,并与实际倒塌过程相对比。通过模拟发现,在距离地面约1/3、1/2、2/3处有应力集中现象,这些部位容易在倾倒过程中折断,这与理论计算、实际结果相吻合。有限元软件ANSYS/LS-DYNA能较好地模拟砖烟囱爆破拆除倾倒过程,烟囱体折断的位置和砖体的力学性能密切相关,这对砖烟囱等高耸构筑物爆破拆除的理论研究和工程实践有一定的借鉴意义。

In the bla.sting demolition work of brick chimney, both the height of brick chimney and the difficulty of its demolition work are increasing. Mechanics principles were adopted to establish the collapse model of brick chimney. Moreover the mathematical methods were also used to derive the area of chimney maximum bending moment, which allowed the possibility of numerical simulation for the collapse process of the brick chimney. It was revealed that there was a phenomenon of stress concentration on the parts at distances of 1/3, 1/2, 2/3 from ground, which were easy to be broken during the process of dumping. This was identical to theoretical calculation and actual results. The finite element software could simulate the collapsing process of brick chimney blasting demolition better and the broken place of chimney was related to the mechanical property of brick-concrete structure itself, which had profound guiding significance on theoretical research and engineering practice of the blasting demolition of high-rise structures such as brick chimney.