Abstract:Research purposes: When wanting to build a bridge over dissymmetrical vaHeys,a long connecting,high pile.1arge—span and dissymmetry continuous rigid—frame bridge is a better choice.Compared with rigid—frame continuous beam bridge,this type of bridge has many advantages,such as good stability,relatively easy construction,beautiful shape and easy maintenance.This paper analyzes and researches the the characteristics of the load bearing capacity and deformation of the structure,closure sepuences and closure mersures,the influence of large ratio between side span and mid—span on the structure,and the safety in cantilever construction for providing the reference to the similar construction.
Research conclusions:The beam bending moment,the longitudinal horizontal displacement of piers and the bending moment of pier cross—sections of long connecting,high pier,large—span and dissymmetry continuous rigid—frame bridge are all dissymmetry.The closure thrusting can obviously decrease the bending moment on the top and bottom of piers.The decreasing range is not only relative to the pier stiffness,but also to the distance between piers and the zero displacement point.Wether the closure thrusting force is loaded or not has little effect Oil the beam bending moment.Forthis type of bridge,if the closure thrusting is needed,the closure sepuenees from the mid—span to secondary side span to side span should be followed,which can lower the closure cost and speed up the construction process.When thrusting,the reinforcing steel bars and the temporary memberfl for fastening two ends of cantilevers in the closure area should not be welded each other and should be kept horizonally movable.If the ratio between the side span and the mid—span is large,the effective action must be kaken to prevent the crack of web of the beam.Because of needing the load on the structure after closing,the permanent cross girders on side piers should not be installed,but temporary cross girders are necessary for the stability of hish piers in the stage of cantilever construction.
刘志军. 长联高墩大跨不对称连续刚构桥设计与施工研究[J]. 铁道工程学报, 2010, 27(12): 31-36.
LIU Zhi—jun. Reserch on Design and Construction of Long Connecting,High Pier,Large——span and Dissymmetry Continuous Rigid—Frame Bridge. 铁道工程学报, 2010, 27(12): 31-36.
Chen Lie,Xu Gongwang.Selection of Structural Types and Closure Sequences for Long--span and High·-rise Pier PC Bridge[J].Bridge Construction,2005(1):33—51.
Li Xinglin.Liao Chengqiang.Reinforcement Oeagn of 160 m Span Prestressed Concrete Continuous RigidFrame Box Girder[J].Journal of Railway Engineering Society,2008(4):42一46.
[9] 董盛围.悬灌连续梁中跨合拢的约束锁定施工[J].铁道工程学报,1996(3):62—66.
Dong Shenggno.Construction Works for Connecting Two Cantilever Arms of Middle Span of Continuous Girders by Suspension Grouting with Restricted Locking Measures[J].Journal of Railway Engineering Society, 1996(3):62一66.
Yao Guowen,Song Wenfeng,Zhou Zhixiang. Optimization of Horizontal Thrust and Closure Sequences for Multi—-span Continuous Rigid-—frame Bridge[J].Highways&Automotive Applications,2008 (1):91—93.