The Analysis Of Stability And Construction Control Of Concrete Filled Steel Tube Arch Bridge

In recent twenty years, with the highway in a mountainous area, the building number and span of concrete filled steel tube arch bridge are growing., With the increase of span, the stability problems of arch bridge are becoming more and more prominent, the construction is becoming more difficult.Relying on the Longqiao large bridge, this paper analyzed the operational phase stability and the construction process control of long span concrete filled steel tube arch bridge. The main contents are as follows:Based on the nonlinear finite element numerical calculation method as the basic method,using general finite element software for computing tools, analysis of the concrete filled steel tube composite structure characteristic simulation of double material model, material model and the advantages and disadvantages of the conversion, conversion material of model of unified theory background engineering simulation calculation.Using the finite element software ANSYS 12.1 to eigenvalue buckling analysis of the Longqiao large bridge,geometric nonlinear buckling analysis and dual nonlinear buckling analysis.The results show that the linear elastic analysis is the unsafe for the wind-resistant design;After considering geometric nonlinearity of structure safety factor by nearly 6%;Considering the dual nonlinear structure stability safety coefficient by nearly 45%;Stability analysis in practical engineering dual nonlinear geometrical and material ought to be considered at the same time.Established by using finite element software MIDAS civil 2015 multiple sets of space model, researched the wide span ratio, steel ratio, arch on the pillar and the lateral brace layout and parameters, "X" and "I" combined lateral brace effect on the stability of the bridge,suggested that the position is advantageous to the arch bridge stability lateral brace layout.Construction control is an important way to ensure the safety of long-span bridge construction and to realize the expected design target, by applying appropriate temporary buckle cable force in construction control is the important construction method of concrete filled steel tube arch bridge, arch rib concrete pumping sequence is an important means to adjust,which control internal force distributionof two materials during construction. Based onthe effect matrix method, using the unknown load coefficient optimization function,of MIDAS civil analyzes the reasonable cable force of the temporary cable during arch rib assembling.Using the method of construction joint section, analyze the structure stress influence of four different perfusion of arch rib concrete scheme,which are the first last quarter after the first quarter after the lateral medial, lateral and bottom chord first after the inside of the first quarter after the first after the outside inside, the inside of the posterolateral,the stress and displacement of steel tube arch rib and pumped concrete are optimal control objectives, suggested that the reasonable cable force and arch rib pumping concrete scheme.