Study On Hoisting Construction Of Steel Concrete Composite Beams Of Liangqing Suspension Bridge In Nanning

The steel-concrete composite beam has been gradually widely used in the field of civil engineering as for its strong spanning capacity,significant economic benefits and other advantages.It has also been applied to suspension bridge construction in recent years.The scholars at home and abroad on steel concrete composite beam mostly focuses on all aspects of performance of laminated surface,such as strength,slip,shear connection,stress strain,crack resistance and deflection,they pays little attention on the stress analysis of composite beam combination in the construction process.This paper analyzes the steel concrete composite beam bridge hoisting construction problems in the process of Nanning Liangqing ratio steel concrete composite beam bridge design and construction.The main contents and results are as follows:(1)Literature review.The characteristics of the steel-concrete composite beam bridge structure are sketched,the development process and the current research of reinforced concrete composite beam stack suspension bridge are expounded,and the suspension bridge steel concrete composite beam and the main components of laminated steel box girder bridge deck construction methods and construction technology are summarized.(2)The Ansys finite element analysis software is used to calculate modeling of ratio of hoisting equipment for steel box girder of suspension bridge span cable crane,to analyze the stress state of cross cable crane in the vertical lifting steel box girder and swing lift steel box girder under different working conditions,to do checking analysis of the truss rod the force and stability.It provides a theoretical basis of the safety of truss structure in the construction process.It also verifies the feasibility of application of cross cable crane in the ratio of width to span suspension bridge steel box girder hoisting construction.(3)With the establishment of the suspension bridge Midas bridge construction stage analysis model,tracking simulation in the process of steel box girder construction,the free slip curve law of main saddle and the variation law of bottom stress in the steel box girder hoisting process are calculated and analyzed.Based on these data,the reasonable timing of the main cable saddle and the layout scheme of pushing quantity are determined.At the same time,with the analysis of the combination of the construction stage and the reversed construction stage,the linear analysis of the steel box girder of suspension bridge under typical conditions is carried out.Based on the theory of non stress state control,a reasonable steel box girder making line is determined,which solves the problem of linear control in the construction of steel box girder of suspension bridge.(4)Based on the engineering background of prefabrication and hoisting of bridge deck,four kinds of construction sequence schemes are proposed,which are longitudinal bridge to one-way asymmetric pavement,two-way symmetrical pavement and multi way symmetrical pavement.And the finite element analysis software Midas civil is used to establish 4 kinds of bridge deck construction under the order of the inverted model.According to the calculation and analysis,the law of the stress and the linear change of the steel beam in the process of the construction of the bridge deck is studied,which with the comparison of the comprehensive construction period and the construction cost factors provides the technical basis for selecting the reasonable bridge deck paving sequence.