180 m同轴超高复杂结构烟囱拆除爆破

Demolition blasting of 180 m coaxial ultra-high complex structure chimney

为了爆破拆除由183 m高钢结构内筒和外部180 m高钢筋混凝土烟囱组成复杂结构钢内筒混凝土烟囱,通过综合考量该烟囱的复杂结构特点、工程周边环境、施工安全等关键因素,最终确定采用外部结构定向控制爆破、钢内筒结构聚能切割的相结合方法,异步整体一次爆破拆除技术方案。首先对该烟囱两部分筒体进行切口预处理,根据其结构特征,外部钢筋混凝土烟囱类梯形切口加定向窗设计、内部钢筒采用梯形切口并且预留对称支撑结构,并且将烟囱内筒已有的检修平台使用槽钢与钢内筒焊接在一起,烟道口处的钢内筒与混凝土外壁的导流板进行加固,确保拆除爆破时形成协同定向导向作用。考虑到钢内筒的钢筒壁薄、强度高、韧性大等特点,优化爆破拆除时差确定选择精度高的数码电子雷管进行分部分段起爆,确保其倒塌时序实现完美同步定向拆除爆破。最后通过设计防护网、减振沟、减振堤等减小倒塌烟囱触地振动及飞石。结果表明:总体爆破设计方案合理,爆破效果达到预期目标,该工程爆破技术应用及创新设计可为类似工程提供重要参考。

Within 183 m high steel structure for blasting demolition by tube and external within 180 m of high reinforced concrete chimney complex structural steel tube concrete chimney,through the comprehensive consideration of the chimney complex peripheral environment and construction of the structural characteristics,key factors,such as safety ultimately determined using external structure of directional controlled blasting,steel tube structure shaped cutting method of combining Technical scheme of one-step overall blasting demolition.First of all,the two parts of the chimney barrel were pre-cut.According to its structural characteristics,the trapezoidal cut and directional window design of the external reinforced concrete chimney,the trapezoidal cut of the internal steel cylinder and the symmetrical support structure are reserved,and the existing maintenance platform of the chimney inner cylinder is welded together with the channel steel and the steel inner cylinder.The steel inner cylinder at the flue mouth and the guide plate of the concrete outer wall are reinforced to ensure that the synergistic directional guidance effect is formed during the demolition blasting.Considering the characteristics of thin wall,high strength and toughness of the steel inner cylinder,the time difference of blasting demolition is optimized to determine the selection of digital electronic detonator with high precision for segmental initiation,so as to ensure the perfect synchronous directional demolition blasting of its collapse sequence.Finally,the vibration and flying rock of collapsed chimney can be reduced by designing protective net,damping ditch and damping dike.The results show that the overall blasting design scheme is reasonable and the blasting effect reaches the expected goal.The application of blasting technology and innovative design of this project can provide important reference for similar projects.