京港澳高速5号跨线天桥爆破拆除技术研究

Research on Blasting Demolition Technology of Overpass No. 5 on Beijing-Hong Kong-Macao Expressway

摘要: 文章以京港澳高速公路5号跨线刚架天桥爆破拆除为工程背景，针对桥梁高次超静定结构特性与周边复杂环境，开展控制爆破拆除技术研究。提出拱肋、斜撑、桥面三区毫秒微差起爆技术，实现整体向内坍塌与充分解体；构建高速公路路面与国防光缆一体化分层防护体系，有效控制爆破飞石危害；建立爆破振动与塌落振动监测。工程实践表明，该爆破方案设计合理、安全可控，可在12 h内完成爆渣清运与道路恢复，可为同类运营高速公路上跨天桥爆破拆除提供技术参考。

Abstract: Taking the controlled demolition of Overpass No. 5 on the Beijing-Hong Kong-Macau Expressway as a case study, this research investigates controlled demolition techniques in response to the bridge’s highly statically indeterminate structural characteristics and the complex surrounding environment. A millisecond time-delay detonation technique was proposed for three zones—the arch ribs, diagonal braces, and bridge deck—to achieve a controlled inward collapse and complete disintegration; an integrated, layered protection system combining the highway pavement with national defense optical cables was established to effectively mitigate the hazards of flying debris from the blast; a monitoring system for blast and collapse vibrations was also implemented. Engineering practice has demonstrated that this blasting plan is well-designed, safe, and controllable, allowing for the completion of debris removal and road restoration within 12 hours. It provides a technical reference for the controlled demolition of similar overpasses on operational expressways.