某宽幅矮塔斜拉桥Y形桥塔施工方案优化  

Construction Scheme Optimization for Y-Shaped Pylons of a Wide Extradosed Bridge

作　　者：朱强 艾华 张美玲 ZHU Qiang;AI Hua;ZHANG Mei-ling(Guangzhou Nansha District Construction Science and Technology Service Center,Guangzhou 511455,China;Yichang Housing and Urban Rural Development Bureau,Wuhan 443699,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China)

机构地区：[1]广州市南沙区建设科学技术服务中心,广东广州511455 [2]宜昌市住房和城乡建设局,湖北宜昌443699 [3]桥梁结构健康与安全国家重点实验室,湖北武汉430034 [4]中铁大桥科学研究院有限公司,湖北武汉430034

出　　处：《世界桥梁》2023年第2期47-52,共6页World Bridges

摘　　要：某(105+180+105) m波形钢腹板-PC组合梁矮塔斜拉桥桥塔采用外倾式分肢双塔柱,外倾15°,外观呈Y形。针对桥塔先塔后梁施工过程中上塔柱塔根内侧拉应力和塔顶横向变形过大的问题,提出先塔后梁增加临时对拉索和塔梁同步施工2种施工优化方案,采用MIDAS Civil软件建立有限元模型,研究各施工优化方案对桥梁结构受力性能的影响,并进行综合比选。结果表明:施工过程中,2种施工优化方案均能将塔根拉应力减小至材料抗拉强度设计值以下,且塔梁同步施工方案塔顶横向变形比先塔后梁施工方案最大减小40.2%;成桥状态时,2种施工优化方案的斜拉索成桥索力值与设计成桥索力值比较接近,且误差均在5%以内,2种施工优化方案对成桥质量控制无不利影响;通过工期、工程造价、工程质量和施工安全方面的比较,经综合考虑,该桥桥塔施工采用塔梁同步施工方案。工程实践证明塔梁同步施工方案实施效果较好。The case bridge in this study is an extradosed bridge with a main span of 180 m and two side spans of 150 m. The bridge features its composite deck that consists of corrugated steel webs and PC box girders. The pylon is a Y-shaped structure, in which the two upper columns incline outwardly at 15°. If the pylons were constructed ahead of the deck, there would be excessive tensile stresses in the inner side of the pylon roots and oversized pylon-top transverse displacement. To find a better solution, two optimized construction schemes, either to construct the pylons ahead of the deck with temporary pull-back cables or to construct the pylons and the deck in parallel, were compared. Finite element models were developed in MIDAS Civil to analyze the load bearing behavior of the bridge under these two optimized construction schemes. The results demonstrate that using either of the two optimized construction schemes, the stresses in the pylon roots can be reduced below the design material tensile strength. When the pylons and the deck were constructed in parallel, the pylon-top transverse displacement was reduced by a maximum of 40.2%. Both optimized construction schemes enable stay cable forces to approximate the design values after completion of the bridge, with errors within 5%. The two optimized construction schemes won′t exert adverse effects on the quality control of the completed bridge. Compared comprehensively from aspects of construction schedule, engineering costs, quality and construction safety, the synchronized pylon and deck construction scheme was selected, and the engineering practice proved the efficiency of the scheme.

关 键 词：矮塔斜拉桥 Y形桥塔 施工方案 塔梁同步 先塔后梁 对拉索 有限元法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]