| The single-column pier bridge has the advantages of beautiful structure,low cost and small line of sight interference.It can often become the only bridge type selected by most designers at urban overpasses and expressway ramp bridges.However,in recent years,many bridge overturning accidents have occurred.The shadow of the single-column pier curved girder bridge,and the direct cause of the overturning accident of the single-column pier bridge is mostly related to the overload of the vehicle and the driving on the same side.Due to the frequent occurrence of bridge accidents,many of us have concerns,such as : whether there are safety hazards and congenital deficiencies in the bridge structure of single column pier,whether there are defects in the design theory of single column pier bridge,especially in the case of large traffic volume and serious vehicle overload in China,what kind of way should be taken to avoid accidents in the existing single column pier bridge,and whether the single column pier bridge can continue to be built in the future planning and construction of urban and high-speed bridges.The biggest disadvantage of single-column pier bridge is that there is only one pier in the middle and it does not have torsion resistance,resulting in weak torsion resistance at the beam end.When the vehicle is overloaded and driving on one side,the bridge overturning accident is prone to occur.Once the overturning accident occurs,it will cause huge economic losses to the country.Therefore,it is of practical value to study the anti-overturning stability and reinforcement of single-column pier bridges.Based on an engineering example,this paper establishes a finite element model through Midas 2021,and carries out corresponding research work on the lateral anti-overturning stability of single-column pier bridges.The main contents are as follows:(1)The force characteristics and overturning reasons of single-column pier bridge are analyzed.The general differential equation of single-column pier curved girder bridge is established.The relationship between structural displacement,torsion angle and external load is described from the perspective of differential equation.(2)Through the comparative analysis of two methods for calculating the anti-overturning coefficient of single-column pier,the overturning axis calculation method and the bearing failure method,it is found that the stability coefficient calculated by the overturning axis method meets the specification,while the stability coefficient calculated by the bearing failure method does not meet the specification.The main reason is that the overturning axis method only considers the rotation of the beam without considering the relative torsion and deflection deformation,while the bearing failure method considers the torsion deformation of the beam and the redistribution of the bearing reaction force.Therefore,the stability coefficient calculated by bearing failure is more conservative.(3)The finite element software Midas 2021 is used to study the radius of the single column pier curved beam bridge,the spacing of the beam end support,the single column double support of the single column pier,the pre-eccentricity of the support and the temperature effect.The corresponding finite element model is established,and the influence law of the anti-overturning stability of the single column pier is analyzed by whether the inner and outer supports of the beam end are separated and whether the anti-overturning stability coefficient meets the specification.(4)In this paper,three reinforcement methods are proposed,and the relevant calculation and analysis are carried out through the theoretical research basis of this paper.The research shows that the three reinforcement schemes can improve the anti-overturning performance of single-column pier bridges.The specific reinforcement method should be considered from the aspects of safety,economy,durability and reinforcement effect of the bridge. |
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