复杂环境下钢筋混凝土简支梁式桥爆破拆除

摘要

介绍了城市复杂环境下钢筋混凝土简支梁式桥梁爆破拆除实例.根据待爆破桥梁自身结构特点及周围环境要求,采用浅孔爆破和深孔爆破相结合的爆破拆除施工方案.桥墩、台帽、联系梁采用浅孔爆破,南北两端承台基础采用中深孔爆破技术一次性爆破拆除.在保证桥梁结构安全的条件下,对桥梁南北两跨及部分桥面进行了预处理.为了增加桥梁构件部分空中解体效果及减少爆破后二次破碎量,起爆网路采用由北向南逐跨逐段延时起爆技术.在施工过程中进行精细化管理,对爆破参数进行优化,严格控制钻孔质量,采取有效的安全防护措施,对重点对象景观"中隔墙"采取缓冲垫层进行防护.爆破达到了预期的爆破效果,桥体空中解体较为充分,爆破有害效应没有对周边建构筑物造成影响,重点保护对象"中隔墙"完好无损.%The explosive demolition example of reinforced concrete simply supported beam bridge in urban com-plex environment was introduced.According to structural characteristics of the blasting bridge and requirements of surrounding environment,the explosive demolition scheme was designed combining the shallow hole blasting and deep hole blasting.The shallow hole blasting was applied to the pier,abutment cap and contact beam.The north and south ends pile foundation were demolished with medium-length hole blasting technology simultaneously.To ensure the safety of the bridge structure,two spans in the bridge north and south and some bridge decks were treated in ad-vance.In order to increase the midair disintegration effect of bridge components and to reduce secondary crushing a-mount after blasting,the priming circuit was designed with time delay initiating technique of span by span blasting from north to south.During blasting,the fine management was carried out and the blasting parameters were further optimized.Effective safety measures were taken to protect the key landscape"mid-partition"by cushion.Good blas-ting results were obtained,and the midair disintegration of blasting target was relatively complete,meanwhile no influ-ence was made on the surrounding buildings,and the key protection object"mid-partition"was intact enough.