紧临重要建筑物碍航双曲拱桥爆破拆除  

Explosive Demolition of Double Arched Bridge Obstructing Navigation in Close Proximity to Important Buildings

作　　者：李贵阳 熊英建 LI Gui-yang;XIONG Ying-jian(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan 430040,China)

机构地区：[1]中交第二航务工程局有限公司,武汉430040

出　　处：《爆破》2023年第2期124-132,共9页Blasting

摘　　要：艳洲电站大桥位于艳洲枢纽工程新建船闸、电站及泄水闸拟建坝址上,根据工程建设进度安排,对该桥予以拆除。艳洲电站大桥为双曲拱桥,桥梁全长180.0 m,桥面宽8 m,其地处彭山旅游风景区,周边有多处名胜古迹、企业厂房,环境复杂,与紧临既有电站大坝最近处为8 m,与电站大坝箱梁桥紧接并共用一个桥台。限于现场作业条件,最终决定采用爆破拆除工艺。为确保整个桥体可靠倒塌且解体充分、钢筋混凝土分离,采取抛掷爆破装药炸碎拱肋、拱柱、连梁等构件,单耗为1.2~1.5 kg/m^(3)。采用加强松动爆破炸毁桥墩,最大单墩药量为480 kg,按照左重右轻的原则,使整桥似骨牌式向右岸方向倒塌。采用孔内延时孔外接力传爆网路,即孔内雷管采取MS12段,孔外工业电子雷管并联,起爆顺序为由左岸向右逐跨、墩起爆,保证桥体平稳逐跨有序垂直塌落,且不会对左岸桥台形成挤压冲击。通过在靠近左岸电站、滚水坝沿线100 m水下,预先敷设漏气PVC,用空压机向管内打压形成气泡帷幕,有效减小水击波超压,从而降低了爆破振动和水击波对周边建(构)筑物的影响。The Yan Zhou power station bridge was built on the proposed structure site of the Yan Zhou hub project,which included construction of a new ship lock,power station,and spillway gate.Due to the progress of the engineering construction,the bridge was dismantled.The Yan Zhou power station bridge is a hyperbolic arch bridge with a total length of 180.0 m and a width of 8 m.It is located in the Pengshan tourist scenic area,surrounded by many famous historical sites and enterprise factories.The environment was complex,and the nearest distance from the bridge to the existing power station dam was 8 m.The reinforced concrete box girder bridge of the power station dam was adjacent and shared a bridge pier with it.Due to the working conditions on-site,blasting demolition was adopted.In order to ensure the reliable collapse and complete disassembly of the entire bridge,as well as the separation of steel bars and concrete,the components such as arch ribs,arch columns,and connecting beams were pulverized through throwing explosive devices,with a powder factor of 1.2~1.5 kg/m.Reinforced loose blasting was used to destroy the bridge piers,and the maximum explosive charge for a single pier was 480 kg.According to the principle of heavy left and light right,the entire bridge was collapsed toward the right bank direction like a domino.An inner-hole delay and out-hole relay initiation network was used.The MS12 detonator was used for the inner-hole delay,and the industrial electronic detonators were used in parallel out of the holes.The blasting order was from left bank to right bank,and then from pier to pier,to ensure that the bridge collapsed orderly and vertically,without causing crushing impact to the left bank bridge pier.A leaky PVC was pre-laid underwater along a 100m line near the left bank power station and water roller dam.An air compressor was used to press the air into the pipe to form an air bubble curtain,which effectively reduced the water shock wave overpressure,thereby reducing the impact of blasting vibration and

关 键 词：双曲拱桥 爆破拆除 紧临建筑物 抛掷爆破 气泡帷幕 

分 类 号：TU746.5[建筑科学—建筑技术科学]