摘要
云南月亮湾大桥主桥为主跨465m的双塔单跨悬索桥,加劲梁采用预应力混凝土梁结构,采用节段预制与湿接缝现浇施工,全桥共76道湿接缝(宽50cm)。针对湿接缝混凝土浇筑顺序与配重措施对加劲梁内力和线形的影响,提出3种湿接缝浇筑方案:无配重下由桥塔向跨中方向浇筑(方案1),无配重下由跨中向桥塔方向浇筑(方案2),全桥一次性配重、逐段置换浇筑(方案3)。采用MIDASCivil软件建立全桥有限元模型,分析3种方案的成桥线形与湿接缝应力,并从适用性、安全性、经济性及工期等方面进行综合比选,选择方案3。采用方案3施工时,需对19道湿接缝进行纵向预偏(预偏量9.5mm/道),以保证加劲梁的无应力长度。实践证明,采用方案3施工,大桥结构受力合理、线形平顺、结构安全、工期短。
The main bridge of Yueliangwan Bridge in Yunnan Province is a two-tower suspension bridge with a single span of 465 m.The prestressed concrete girder structure,which is constructed by precast segmental method,is adopted,and the girder segments are connected by wet joints.A number of 76 wet joints (each 50 cm in width) are cast for the full bridge.Given that the casting sequence of the wet joints and the way to implement counterweights would have influence on the internal forces and geometrical shape of the stiffening girder,three wet joints casting schemes are proposed,including casting from the towers towards the midspan without counterweights (scheme 1),casting from the midspan towards the towers without counterweights (scheme 2),and implementing the counterweights at one go and casting the wet joints segment by segment to displace the counterweights (scheme 3).The software MIDAS Civil is used to establish the finite element model of the overall bridge,to analyze the geometry of the completed bridge and the stresses in the wet joints when different wet joints casting schemes are used. The three schemes are compared from aspects of applicability,safety,economic performance and construction schedule,and scheme 3 is finally chosen.By scheme 3,in the process of implementation,longitudinal pre-offsetting amount should be reserved at the locations of 19 wet joints (9.5 mm at each wet joint) to ensure the stress-free length of the stiffening girder.The engineering practice proves that scheme 3 is superior to the other schemes,which can ensure the rational load bearing performance and smooth geometrical shape of the bridge,safety of the bridge structure as well as short construction time.
作者
陶路
马旭明
彭旭民
黄盛
TAO Lu;MA Xu-ming;PENG Xu-min;HUANG Sheng(China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China;State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;Guizhou Bridge Construction Group Co.,Ltd.,Guiyang 550001,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2019年第A01期121-126,共6页
Bridge Construction
关键词
悬索桥
预应力混凝土梁
湿接缝
浇筑顺序
有限元法
纵向预偏
方案比选
suspension bridge
prestressed concrete girder
wet joint
casting sequence
finite element method
longitudinal pre-offsetting
scheme comparison
