高耸建筑物定向爆破中切口长度安全范围的研究

爆破拆除高耸筒体结构时 ,爆破切口长度的合理选取是爆破成功的重要因素。目前的实践经验 ,爆破切口长度取为切口处筒体圆周长的 6 0 %～ 6 6 % (即 3/ 5～ 2 / 3) ,按此取值范围进行施工 ,爆破效果的好坏并存 ,事故仍有发生 ,这说明此取值范围偏大。借助有限元软件ANSYS ,通过数值计算 ,可获得起爆瞬间 ,在结构自重作用下引起的爆破切口支撑部的应力与应变状态 ,因而 ,可分析出爆破切口长度较安全的取值范围。对比实际拆除爆破的效果 ,爆破切口长度取切口处筒体圆周长的 6 2 %～ 6 4 %是比较安全适宜的。数值分析所得出的结论 ,对爆破设计施工有一定的借鉴意义

Study on the Safe Range of Blasting Cut Length in Directionally Blasting the Towery Building

During the blasting demolition of the towery building,choosing rational length of blasting cut is crucial to the success of the blasting. According to the current practice experience,the length of blasting cut is 60%～66% of the bottom perimeter in the blasting areas of a towery building. However,the blasting results are not always successful in spite of the experiential range. It indicates that the experiential range of blasting cut is too wide. By means of finite element software ANSYS,stress distribution along the support part of blasting cut under the weight of the chimney could be obtained through numerical calculation and safer range of blasting cut length could be got. Compared with the results of the demolition engineering practice,it concludes that the length of blasting cut ranging from 62 % to 64 % of the bottom perimeter would be safer and more reasonable than from 60% to 64%. This conclusion would be useful for blasting design and construction.