Research On Anti-overturning Stability Of Curved Girder Bridges With Single-column Piers

With the deepening of urbanization in China,the curved girder bridges with single-column piers have been widely used in the hub interchange of urban interchange systems and high-grade highways due to its beautiful linear,strong environmental adaptability,and strong traffic flow diversion ability.However,in recent years,there have been many overturning accidents of single-column piers bridges,which have caused huge property losses and bad social impacts on the country.Although vehicle overload is the main cause of accidents,as a bridge designer,it is impossible to take overloading as a technical standard to design bridges,but we should deepen the understanding of overturning problems,so as to improve the anti-overturning stability of curved girder bridges with single-column piers at the design level,to avoid the recurrence of overturning accidents.In view of this,it is of great practical significance and engineering value to study the anti-overturning stability of curved girder bridges with single-column piers.In this paper,a curved girder bridge with single-column piers is taken as the research object,and the corresponding research work on its overturning stability is carried out through numerical simulation.The main contents are as follows:（1）Research on anti-overturning performance of curved girder bridges with single-column piers based on current specifications.The finite element model of the bridge is established by Midas/Civil software,and its overturning stability under different moving load conditions is analyzed.Further from the nature of the overturning process,a method is developed based on the specification to determine the maximum vehicle load limit that a bridge can withstand while meeting the overturning stability requirements.The research results show that the bridge meets the specification requirements under the lane load,but compared with the fleet load in actual operation,the overturning effect produced by the "virtual load" mode of the lane load is small;when a typical vehicle crosses the bridge with a single vehicle,there is no risk of the overturning of this bridge,when two,three and four vehicles are lined up longitudinally to cross the bridge,the bridge will overturn when a single vehicle is overloaded by only 190%,100%,and 50%.In contrast,the bridge-crossing conditions and data obtained by the analysis of this bridge are in good agreement with the actual overturning accident,which shows that the method used in this paper has certain practical significance.（2）Analysis of the influence of the parameters on the anti-overturning stability of the curved girder bridges.Using the single-column pier bridge as the sample bridge,the finite element software Midas/Civil was used to establish the finite element models with different curve radii,different double bearing spacing at beam end,and different ratio between side span and main span,to explore the influence of different parameters on the overturning stability of the structure.The research results show that the anti-overturning stability of the curved girder bridge with single-column piers increases with the increase of curve radius;the anti-overturning stability of the bridge shows an increasing trend with the increase of the double bearing spacing at beam end;the larger ratio between side span and main span,the higher the anti-overturning stability of the bridge.（3）Sensitivity analysis of anti-overturning stability parameters.The sensitivity analysis of the parameters affecting the anti-overturning stability of the curved girder bridges with single-column piers is carried out by the combination of orthogonal experiment and grey theory,and the main factors affecting the anti-overturning stability of the curved girder bridges with single-column piers are obtained.The research results show that the double bearing spacing at beam end is the most sensitive to the anti-overturning stability of the curved girder bridges with single-column piers.（4）Analysis of engineering improvement measures to enhance anti-overturning stability.For single-column piers bridges in different stages,some measures to improve the anti-overturning performance are discussed.The research results show that for multi-span curved girder bridges with single-column piers,avoiding continuous single-support design can effectively improve the anti-overturning performance of the structure.Figure [54] table [23] reference [73]...