高耸冷却塔原地塌落爆破工艺分析

Analysis on Blasting Technology of In-situ Collapse of High-rise Cooling Tower

为了研究冷却塔原地倒塌爆破工艺,采用有限元软件进行切口模拟分析,用高清摄像头对筒体及人字形立柱变形进行数据采集,针对筒体变形时间、塌落速度、切口闭合变化、筒体扭曲变形后塌落范围情况进行了详细的分析。实践结果表明:冷却塔原地塌落切口设计并不能按常规4等分平均分配,四个区域对等分配易造成整体下座不倒,第四个区域周长(最后引爆)略大第一区域四分之一,四个区域孔内延期时间分别为MS4/MS8/MS8/HS3孔外为MS2;通过有限元软件模拟筒体产生塌落趋势需要1 s,筒体的开槽口产生闭合需要3 s,筒体空中挤压扭曲触地需要6.8 s,各区域孔内延期时必须在合理时间内完成变形工作,经爆后影像分析测算与模拟时间相同,原地塌落筒体90%在池内,上部圈梁外抛出水池约6 m,对周边制氢站、循环水泵房、钢闸门等设施未造成影响;未对23 m外天然气埋管造成影响,经测量天然气管网塌落振动值仅2.095 cm/s说明原地塌落爆破技术对于触地减震起到较大作用,能有效控制筒体塌落外抛距离。

In order to study the blasting technology of the in-situ collapse of a cooling tower,the incision was analyzed by finite element software.Furthermore,a high-definition camera was used to collect the deformation data of the cylinder body and lambdoid stand columns.Then detailed analysis was carried out for the deformation time of the cylinder,the collapse speed,the change of the incision closure,and the collapse range after the distortion and deformation of the cylinder.The practice results show that the incisions for the in-situ collapse of the cooling tower cannot be designed as four equal parts as convention.It is easy for four equally distributed parts to cause the bottom part not to collapse.The perimeter of the fourth area(the last initiated part)is slightly larger than that of the first area by a quarter.The in-hole delay times in the four areas are MS4,MS8,MS8 and HS3,respectively,and the out-hole delay time is MS2.Through the finite element simulation,it takes 1 second to generate the collapse trend of the cylinder,3 seconds to close the incisions of the cylinder,and 6.8 s for the cylinder to squeeze,twist in the air and touch the ground.The deformation of each area must be completed within a reasonable time.By image analysis and calculation after the explosion,the above simulated times are the same as the actual times.90%of the in-situ collapsed cylinder is within the pool,and the upper ring beam is thrown out of the pool by about 6 meters,which does not affect the surrounding hydrogen production station,circulating water pump room,steel gate and other facilities.After measurement,the peak vibration velocity the natural gas pipe is only 2.095 cm/s,indicating no impact on the buried gas pipe 23 meters away.The research shows that the in-situ collapse blasting technology can effectively control the collapse touch-down vibrations and the collapse throw distance of the cylinder.