Analysis And Calculation Method Of Anti-overturning Stability Of Curved Box Girder Bridge With Single Pillar Pier

In recent years,there have been many overturning accidents of single-pillar pier curved box girder bridges in our country,which bring extremely unfavorable influences on public opinion.At present,the research on the overturning mechanism of single-pillar pier curved box girder bridges has made great progress.Relevant domestic departments are actively carrying out the investigation and reinforcement of single-pillar pier curved box girder bridges with hidden dangers of overturning,in order to guide the independent Reinforcement and design of column pier and curved box girder bridge more efficiently.The works in this dissertation can be concluded as follows:(1)Having summarized the current calculation methods for the anti-overturning stability of single-pillar pier curved box girder bridges at home and abroad,and having analyzed the advantages,disadvantages and applicable scope of various calculation methods based on calculation principles and engineering examples.(2)Based on the principle of mechanics,the self-weight of the superstructure is approximately equivalent to a uniform surface load or a concentrated force and a moment is taken on the overturning axis,and a simplified calculation formula for the stability effect is derived.The stability effect calculated by the finite element software is calculated by this method.The ratio of the results is between 0.953 and 0.991,achieved the high accuracy.(3)A practical calculation method for the anti-overturning stability coefficient of a single-pillar pier curved box girder bridge is proposed.The calculation example is analyzed using this practical calculation method.The ratio of the calculated stability coefficient to the stability coefficient in the example is 0.978～1.0.It shows that the practical calculation method has good applicability.This method is used to analyze the stability against overturning of a curved box girder bridge with single-pillar piers.It is possible to obtain a more accurate anti-overturning stability coefficient without the aid of finite element software,which has good engineering application value.(4)Based on the practical calculation method of anti-overturning stability proposed in this dissertation,combined with Midas Civil finite element software,the single-column pier curved box girder bridge with different curvature radius,support spacing,middle pier eccentricity and span layout was carried out.The overturning stability is analyzed,and the change law of the anti-overturning performance of the single-post pier curved box girder bridge under the influence of the above parameters is studied.(5)The anti-overturning stability test study of the single-pillar pier curved box girder bridge reinforcement project was carried out.Taking the reinforcement project of a ramp bridge as the experimental research object firstly,the anti-overturning stability analysis and dynamic characteristics analysis of the ramp bridge before reinforcement are carried out to verify the necessity of the reinforcement project;secondly,the optimum is selected through the comparison of schemes Finally,the reinforced ramp bridge was modeled and analyzed against overturning stability calculation and load test.The results show that the actual reinforcement effect of the project is better.