空心板桥板桁组合加固设计及试验研究  

Design of Using Reinforced Concrete Trusses to Strengthen Hollow Core Beam Bridge and Applicability Testing

作　　者：蒙立和 梁明哲 谢肖礼[2] 谢远忠 勾文鑫 MENG Lihe;LIANG Mingzhe;XIE Xiaoli;XIE Yuanzhong;GOU Wenxin(Guangxi Road and Bridge Engineering Group Co.,Ltd.,Nanning 530011,China;College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Guangxi Honghu Structural Engineering Technology Information Consulting Co.,Ltd.,Nanning 530003,China)

机构地区：[1]广西路桥工程集团有限公司,广西南宁530011 [2]广西大学土木建筑工程学院,广西南宁530004 [3]广西鸿鹄结构工程技术信息咨询有限公司,广西南宁530003

出　　处：《世界桥梁》2023年第4期114-121,共8页World Bridges

基　　金：广西重点研发计划项目(桂科AB18126047)。

摘　　要：为对空心板桥进行抗弯加固,提出一种新型加固方法——板桁组合加固法,在边板上增设钢筋混凝土桁架,通过植筋及新设桥面铺装与原桥连接来对桥梁进行整体加固。以底板出现横向裂缝的某6×16 m六跨钢筋混凝土简支空心板桥为背景,采用MIDAS Civil软件建立一跨16 m空心板梁有限元模型,分析加固前、后桥梁的承载能力,并进行静载试验以验证加固方法的有效性。结果表明:加固后主梁的安全系数由1.03提高至1.31,在活载作用下主梁最大下挠值由3.84 mm变为2.36 mm,桥梁的第1阶模态自振频率提高了28.5%,提高了结构的抗弯能力和刚度;主梁挠度实测值与计算值最大误差12.0%,桁架最大拉、压应力实测值与计算值误差分别为7.1%和6.6%,主梁最大拉应力实测值与计算值误差13.7%,实测值与有限元模型计算值较吻合,表明加固桁架参与桥梁的协同受力。板桁组合加固法能有效提高空心板桥的承载能力和结构刚度,且施工简便,具有良好的经济性。A method to add reinforced concrete trusses to improve the flexural strength of the hollow core beam bridge is presented.The prefabricated reinforced concrete trusses are connected with the edge beams of the hollow core beam bridge via planted reinforced bars,and new deck pavement is placed,to rehabilitate the existing bridge.A reinforced concrete,simply-supported,hollow core beam bridge that consists of six spans of 16 m and has transverse cracks in the bottom slabs is used for a case study.The finite element model of a typical 16 m-long span was built up in MIDAS Civil to analyze the load bearing capacity of the bridge before and after rehabilitation.Static load tests were carried out to verify the effectiveness of the presented method.After rehabilitation,the safety factor of the main girder has been 1.31,rising from the original 1.03.Under the action of live loads,the maximum deflection of the main beam decreased from 3.84 mm to 2.36 mm,the first-mode natural vibration frequency of the bridge is increased by 28.5%,indicating an improved flexural strength and structural stiffness.The maximum difference between the measured and calculated main girder deflections reaches 12.0%,the maximum differences of the measured and calculated tensile and compressive stresses in the trusses are 7.1%and 6.6%,respectively,the maximum difference between measured and calculated tensile tresses in the main beam is 13.7%,in good agreement,proving that the added trusses function well with the original bridge components.The presented method is effective in improving the load bearing capacity and structural stiffness of the hollow core beam bridge,which is easy to be implemented and more cost competitive.

关 键 词：空心板桥 板桁组合加固法 加固设计 有限元法 静载试验 承载力 刚度 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]