摘要
达摩沟大桥主桥为主跨105 m的双幅波形钢腹板预应力混凝土组合梁桥,采用异步悬臂浇筑法施工。针对该桥波形钢腹板架设工作面多、人员调度紧张的问题,基于传统异步悬臂浇筑方案,提出在悬臂初期同时架设2个节段波形钢腹板的优化方案,并通过先行架设腹板的线形控制分析确定采用优化方案的可行节段范围。为验证优化方案的可行性与适应性,采用有限元软件Abaqus建立实体模型模拟其施工过程,对比分析异步悬臂浇筑施工优化前、后结构的受力与变形,并进行实桥应用。结果表明:优化方案下先行架设2个节段腹板的可行范围为2~6号节段,相邻节段腹板的预拱度最大调整值为6.4 mm,优化方案对各节段顶板与底板应力、相邻腹板剪应力及变形的影响均较小,且应力计算值均小于规范要求的强度设计值。施工中偏安全考虑仅在右幅1号墩2~4号节段采用优化方案施工,腹板高程均在可调节范围内,且腹板变形实测值与有限元值吻合良好,证明了优化方案的可行性及适用性。
With the main span length reaching 105 m,the main bridge of Damogou Bridge consists of two superstructures of prestressed concrete girders that act compositely with corrugated steel webs.To facilitate the erection of the corrugated steel webs and effectively manage personnel scheduling,it was proposed to simultaneously erect the corrugated steel webs(CSWs)in two girder segments at the early stage of cantilever casting,and to use the controlled geometry of the previously-erected CSWs to determine the girder segments that were the best choices for the method.The construction process was simulated in Abaqus to verify the applicability and efficiency of the proposed method.The load bearing behavior and deformation of the superstructures before and after the modification of the asynchronous pouring construction(APC).The proposed method was applied to a real bridge.The numerical simulation and engineering practice demonstrated that it was proper to erect the girder segments No.2-No.6 by the proposed method,where the CSWs in the exact girder segment and the next two segments would be erected ahead of the cantilever casting of concrete,and the maximum pre-camber of the CSWs in the neighboring segment should be set at 6.4 mm.The modified method would not induce great variation of the stresses in the top and bottom slabs of each segment,shear stresses in and deflections of the adjacent webs,and the calculated stresses were smaller than design strengths suggested in the code.To minimize the safety risk,the proposed method was only applied to the construction of the girder segments No.2-No.4 at pier No.1 in the right superstructure,allowing the elevations of CSWs to be within controllable ranges.The measured deflections of CSWs were consistent with the numerical simulation,proving the feasibility and effectiveness of the proposed method.
作者
奉思东
贺君
郭宝君
甘波
李春跃
FENG Sidong;HE Jun;GUO Baojun;GAN Bo;LI Chunyue(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;BCEG Civil Engineering Co.,Ltd.,Beijing 100015,China;Huzhou City Planning&Design Co.,Ltd.,Huzhou 313000,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2024年第4期149-156,共8页
Bridge Construction
基金
国家自然科学基金项目(52378127,52211530037)
湖南省自然科学基金项目(2022JJ10049)。
关键词
组合梁桥
波形钢腹板
悬臂浇筑法
异步施工
应力
线形
有限元法
composite girder bridge
corrugated steel web
cantilever casting
asynchronous construction
stress
geometry
finite element method
