The Mechanical Analysis And Optimization Of Small Radius Curved Girder Bridge With The Middle Column Support

With the vigorous development of the bridges in China, the small radius curve of prestressed concrete girder bridges with its advantages of beautiful modelling, small covering area and low cost,are more and more widely applied in the urban traffic system,at the same time, due to the insufficient understanding of this kind of bridge, the engineering accidents and diseases often happen, therefore it is urgent to deeply study the small radius curve beam bridge.This article, based on the load test of a certain bridge in Hunan province, focuses on the structural behavior of the prestressed concrete brige of small radius curve and analyzes the reinforcement measures.The research work and the main results were as follows:(1) According to the calculation theory and numerical calculation method of small radius curve beam bridge, using the general finite element software ANSYS analysing the the mechanical properties such as torque distribution, stress and bearing reaction force under the dead loads, prestress and travelling load, at the same time getting the influence line(surface)of each key section, with it,analyzes the flexural behavior and torion resistance of the structure under the unfavorable load.(2) Founed on the the theoretical analysis, the bridge operation was concluded, on the basis of which, analysis the structure optimization scheme.To the strive improvement of torsional performance with the safety of flexural bearing capacity, analysis the the torsional rigidity of the bridge and torque distribution of span under asymmetric prestresses, the offset of bearing or the strengthen of section stiffness.(3) Based on the static load test of the single column support curve bridge, test the deflection and strain values of each control section at the same time.By the conversion of bending moment of each key section, further comparative analysis the result of test and the numerical calculation.After that, the actual stiffness and bearing capacity of the bridge is evaluated, with the conclusion meeting ‘The Test Method of Long-span Concrete Bridge’.(4)Through the dynamic load test of structure, including the field test, vehicle test and brake test, it is concluded of dynamic parameters such as the measured frequency, natural vibration characteristics and impact coefficient.Combining the fundamental frequency ofstructure from finite element analysis with the measured data, further evaluation of the overall performance was made.