边跨非对称悬臂施工对矮塔斜拉桥合理施工状态影响研究  

Influence of asymmetric cantilever construction at side spans on reasonable construction state of extradosed cable-stayed bridge

作　　者：郭维强 Bruno BRISEGHELLA 陈权[4] 薛俊青[1,2,3] Camillo NUTI GUO Weiqiang;Bruno BRISEGHELLA;CHEN Quan;XUE Junqing;Camillo NUTI(College of Civil Engineering,Fuzhou University,Fuzhou 350108,China;Joint International Research Laboratory of Deterioration and Control of Coastal and Marine Infrastructures and Materials,Fuzhou 350108,China;Fujian Provincial Key Laboratory on Multi-Disasters Prevention and Mitigation in Civil Engineering,Fuzhou 350108,China;College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Department of Architecture,Roma Tre University,Rome 00154,Italy)

机构地区：[1]福州大学土木工程学院,福建福州350108 [2]滨海与海洋基础设施及材料劣化和控制国际联合实验室,福建福州350108 [3]福建省土木工程多灾害防治重点实验室,福建福州350108 [4]兰州交通大学土木工程学院,甘肃兰州730070 [5]罗马第三大学建筑学院,拉齐奥大区罗马00154

出　　处：《合肥工业大学学报(自然科学版)》2025年第1期136-144,共9页Journal of Hefei University of Technology:Natural Science

基　　金：国家自然科学基金资助项目(51778148);可持续与创新桥梁福建省高校工程研究中心开放课题资助项目(SIBERC202203);福建省土木工程多灾害防治重点实验室开放课题资助项目(MPMC-2022-4)。

摘　　要：矮塔斜拉桥通常采用对称悬臂法施工,客观条件可能导致该方法无法采用,需要研究非对称悬臂施工的可行性。文章针对双塔双索面预应力混凝土矮塔斜拉桥开展实桥监测,建立有限元模型,分析合理成桥状态和合理施工状态。考虑背景工程无法采用对称悬臂法的实际情况,基于合理施工状态提出边跨现浇段非对称悬臂施工的2种方案,对比采用2种方案完成边跨现浇段施工后对合理施工状态下主梁的挠度、应力及斜拉索索力的影响。结果表明:采用应力平衡法计算成桥恒载弯矩可行域,并以此为约束条件利用基于影响矩阵法原理的未知荷载系数法可计算合理成桥索力;利用考虑施工阶段的未知荷载系数法计算合理初张拉索力及二次张拉索力,可得到合理施工状态;与方案1相比,采用方案2的主梁最大挠度更小且分布更合理,边跨无索区主梁上缘拉应力更小,斜拉索索力分布更均匀;方案2对矮塔斜拉桥的合理施工状态影响较小,最终可达到合理成桥状态。Symmetric cantilever construction is commonly used for extradosed cable-stayed bridges,however,it will be limited in some cases due to objective conditions.Therefore,the feasibility of the asymmetric cantilever construction should be investigated.In this paper,the field monitoring on a prestressed concrete extradosed cable-stayed bridge with twin pylons and double-cable planes was conducted.The finite element model was built to analyze the reasonable finished state and reasonable construction state of the bridge.Because the symmetric cantilever construction cannot be used in this case study,two asymmetric cantilever construction schemes for the cast-in-situ sections of side spans were proposed based on the reasonable construction state.The influences of two schemes on the deflections and stresses of the girder and the cable forces of the stay cables in the reasonable construction state were compared.The results demonstrate that the stress equilibrium method can be used to calculate the bending moment feasible region of the girder under the dead load in the reasonable finished state.The bending moment feasible region of the girder can be used as the constraint condition to calculate the cable forces in the reasonable finished state by using the unknown load coefficient method based on the influence matrix method.The unknown load coefficient method considering the construction stages was selected to calculate the reasonable initial tensioning cable forces and the secondary tensioning cable forces and to obtain the reasonable construction state.Compared with the mechanical performance of the bridge by using scheme 1,the maximum deflection of the girder by using scheme 2 is less and the distribution is more reasonable,the tensile stress on the upper surface of the girder in the segments of the side spans without stay cables is less and the distribution of the cable forces is more uniform.Consequently,the influence of the asymmetric cantilever construction scheme by using scheme 2 on the reasonable construction state

关 键 词：桥梁工程 矮塔斜拉桥 有限元分析 未知荷载系数法 非对称悬臂施工 

分 类 号：U24[交通运输工程—道路与铁道工程]