高耸烟囱原地坍塌爆破拆除可变直径作业平台研究与试验

Experimental Study on Variable Diameter Working Platform for In-situ Collapse Blasting Demolition of Towering Chimney

原地坍塌爆破拆除技术是突破高耸烟囱在可供倒塌场地严重不足条件下的一种新的爆破拆除技术。该技术的难点在于需在百米高空的多个位置设置高效作业平台,以便快速完成钻孔、装药、堵塞与联网等作业,从而形成多道环形爆破切口。针对上述需求,研制了一种可变直径的吊篮式施工作业平台。该新型作业平台的设计总体思路为:基于对作业过程的分析,明确平台的核心功能,综合考虑作业效率、平台可靠性、工艺适应性及成本等因素,确定了滑动搭板式可变截面整体式吊篮平台方案;针对平台对烟囱外形尺寸的适应性,建立了参数化模型,用于确定针对不同烟囱尺寸时吊篮固定段、滑动搭板段长度、夹角参数的最优值;针对伸缩结构的技术方案进行了比选,选定了钢丝绳牵引方案+四氟乙烯减阻方案。在上述技术方案的基础上,确定了平台的结构方案、安全保障方案、适应性设计方案、安装拆除及使用方案。为验证结构设计的合理性,利用有限元软件,对结构的多种工况进行了受力分析,确保了结构受力的安全性。同时,为了进一步验证平台结构的安全性和功能的可靠性,搭设了专用试验架,对首套试验样机开展了功能试验、荷载试验及可靠性试验等一系列试验,试验表明平台的各项功能均达到了设计预期,结构安全性、功能可靠性均满足要求。平台可以满足高耸烟囱原地坍塌爆破拆除的作业需求,同时也可作为其他各种等(变)截面高耸结构拆除的施工平台。

In-situ collapse blasting demolition technology is a new blasting demolition technology which can break through the condition of serious shortage of collapse space for towering chimneys.The difficulty of this technology is to set up efficient operation platforms at multiple locations at hundreds of meters to quickly complete drilling,charging,stemming and networking,thus forming multiple ring blasting cuts.According to the requirements,a variable diameter hanging basket as a construction platform is developed.The overall design idea of the new operation platform is as follows:The core function of the platform is defined based on the analysis of the operation process,and the variable section basket platform with a sliding plate is selected by comprehensively considering various factors such as efficiency,reliability,adaptability and cost.A parametric model is established to determine the optimal values of the length and included angle of the fixed section and the sliding plate of the hanging basket for different chimney dimensions,which is according to the adaptability of the platform to the overall dimension of the chimney.The technical schemes of the telescopic structure are compared and selected,and finally the steel wire rope traction scheme together with the resistance reduction scheme by tetrafluoroethylene plate is selected.On the basis of the above technical scheme,the structural scheme,safety guarantee scheme,adaptive design scheme,installation,disassembly and using scheme of the platform are determined.In order to verify the reliability of the structural design,the stress analysis of the structure under various working conditions is carried out by using the finite element software.Meanwhile,a special test frame is set up,and a series of tests including functional test,load test and reliability test are carried out on the first test prototype to verify the safety and functional reliability of the platform structure.The test results show that all the functions of the platform reach the design expectations,and the structural safety and functional reliability meet the requirements.The platform can meet the needs of in-situ collapse of towering chimneys by blasting demolition,and can also be used as a construction platform for the demolition of other high-rise structures with variable cross-sections.