钢箱梁桁架式纵隔板疲劳开裂弹性阻尼支撑处治技术  

Application of Elastic-Damping Support Device to Treat Fatigue Cracking of Truss-Type Longitudinal Diaphragms in Steel Box Girder

作　　者：桑毅彩 朱世峰 吴海军[2] 暨仕瑀 邓扬 SANG Yicai;ZHU Shifeng;WU Haijun;JI Shiyu;DENG Yang(CCCC Special Engineering Technology Co.,Ltd.,Wuhan 430071,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil&Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 102616,China)

机构地区：[1]中交特种工程有限公司,湖北武汉430071 [2]重庆交通大学土木工程学院,重庆400074 [3]北京建筑大学土木与交通工程学院,北京102616

出　　处：《世界桥梁》2024年第3期119-126,共8页World Bridges

基　　金：国家自然科学基金项目(51878027);河北省省级科技计划资助项目(225676104H);中交集团青年创新项目(2021-ZJKJ-QNCX08)。

摘　　要：针对钢箱梁桁架式纵隔板中出现的早发性、多发性、再发性疲劳开裂病害,分析桁架式纵隔板病害原因,基于能量法,提出将端部刚接斜腹杆变为端部铰接的弹性阻尼支撑处治技术。研制弹性阻尼支撑装置(Elastic-Damping Support Device,EDSD),将斜腹杆局部切除并安装EDSD,通过EDSD中设置的弹性阻尼单元耗散外部荷载输入结构的大部分能量,保障结构在长期车辆荷载等作用下的安全性和正常使用性能。结合某斜拉桥钢箱梁桁架式纵隔板疲劳开裂处治需求,开展了该处治技术实桥应用,并对其进行有限元分析及实桥监测。结果表明:钢箱梁内斜腹杆局部改造安装EDSD后可大幅降低斜腹杆应力水平,有效降低斜腹杆疲劳易损部位开裂风险,增加疲劳寿命;安装EDSD的斜腹杆上的既有裂缝均无扩展。The causes of early,multiple,and recurrent fatigue cracks in the truss-type longitudinal diaphragms in the steel box girder are analyzed,and based on the energy method,it is proposed to replace the original end rigid connections of diagonals to the hinged elastic-damping support devices(EDSDs).A portion of the original diagonals is cut off and replaced by the EDSD,utilizing the elastic damping units in the EDSD to dissipate most of the energy of external loads imposed on the structure,to ensure the service safety of the structure under long-term vehicle loads.The proposed method has been used in an existing cable-stayed bridge.The finite element analysis and field measurements indicate that after fitted with EDSDs,the stresses in the diagonals are greatly reduced,effectively mitigating the cracking risks of the fatigue vulnerable locations in the diagonals,thus extending the fatigue life of the structure.The existing cracks in the diagonals with EDSDs do not show sign of further propagation.

关 键 词：斜拉桥 钢箱梁 桁架式纵隔板 斜腹杆 疲劳开裂 弹性阻尼支撑装置 处治技术 工程应用 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.35[交通运输工程—道路与铁道工程] U445.7