冲击钻孔施工对临近框架桥拆除影响的数值模拟分析  

Numerical Simulation Analysis on Impact Drilling Construction of Demolition of Adjacent Frame Bridge

作　　者：谢春明 李明国 黄华江 任艳 XIE Chunming;LI Mingguo;HUANG Huajiang;REN Yan(Research and Development Center on Road Transport Safety and Emergency Support Technology & Equipment,Guangzhou 510420;Guangdong Hualu Trasport Technology Co., Ltd., Guangzhou 510420;School of Civil Engineering of Guangdong Communication Polytechnic, Guangzhou 510800)

机构地区：[1]公路交通安全与应急保障技术及装备交通运输行业研发中心,广州510420 [2]广东华路交通科技有限公司,广州510420 [3]广东交通职业技术学院土木工程学院,广州510800

出　　处：《广东公路交通》2021年第4期134-139,共6页Guangdong Highway Communications

摘　　要：某高速公路互通立交主线桥第15~44跨为30×15 m钢筋混凝土结构框架桥,经多次加固后仍存在多处破损、露筋和开裂等病害,需对其进行拆除并同步在两侧修建新桥,拆除方案拟采用整幅拆除和半幅拆除两种方案。新桥桩基础距旧桥最近净距约1.4 m,拟采用冲击钻孔施工工艺。为了解冲击钻孔施工对框架桥拆除的影响,采用有限元软件建立部分框架桥分离式共节点模型,考虑整幅拆除和半幅拆除两种方案,对冲击钻孔施工影响下临近框架桥的力学响应进行数值模拟。结果表明:框架桥整幅拆除方案相对于半幅拆除方案,土体、墩柱沉降值趋于一致,墩柱一层根部混凝土和钢筋受力相同,表明由于左右幅结构相对独立,半幅拆除不会对另半幅桥梁结构造成太大影响。采用冲击钻孔工艺施工,考虑到冲击钻孔过程中需要多次冲击,会引起临近框架桥沉降值以及桥面横向水平位移较大,导致结构承受较大的安全风险,建议改用回旋钻成孔工艺施工。The 15th-44th spans of an expressway interchange main line bridge adopt 30×15 m reinforced concrete frame.After reinforcement for many times,the frame bridge still has many defects such as damage,exposed reinforcement and cracking.It is necessary to demolish and build new bridges on both sides at the same time.The demolition scheme is to adopt two schemes:full demolition and half demolition.The nearest clear distance between the new bridge pile foundation and the old bridge is about 1.4 M.The impact drilling construction technology is proposed.In order to understand the impact of percussive drilling construction on the demolition of frame bridge,the finite element software has been used to establish a separated common node model of frame bridge.Considering the whole demolition and half demolition conditions,the mechanical response of adjacent frame bridge under the impact of percussive drilling construction has been numerically simulated.The results have shown that:the settlement values of soil and pier column tend are as same as those in the whole demolition scheme compared with the half demolition scheme,and the stress of concrete and reinforcement at the root of the first layer of pier column is the same,which indicates that the half demolition will not have much impact on the other half bridge structure because of the relative independence of the left and right structures.Using the impact drilling technology construction,considering the need for multiple impacts in the process of impact drilling,it will cause that the settlement value of the adjacent frame bridge and the transverse horizontal displacement of the bridge deck will become larger,which will cause the structure to bear greater safety risks.Ithas been recommended to change to rotary drilling technology instead.

关 键 词：框架桥 拆除 冲击振动 共节点分离式模型 位移 应力 数值模拟 

分 类 号：U445.6[建筑科学—桥梁与隧道工程]