Research On Rigid Body Instability And Prevention And Control Technology Of Curved Girder Bridge Superstructure

In recent years,the rapid development of my country’s infrastructure construction industry has made great achievements.Among them,curved beam bridges are widely used in urban bridges because of their good linearity,beautiful appearance,and traffic steering function.However,in recent years,the frequent occurrence of bridge overturning accidents has aroused the attention of technicians.At present,the relevant evaluation methods for the anti-overturning stability of curved beam bridges are not deep enough.The overturning axis method used by the predecessor scholars to calculate the anti-overturning stability coefficients idealizes the beam body as a rigid body and ignores its bending,shear,and The combined force of torsion and the state of elastic deformation make the result slightly different from the actual one.Therefore,this paper fully considers the vertical elastic properties of beams and supports,and calculates the anti-overturning stability of curved beam bridges based on the new bridge code.The main work and conclusions of this paper are as follows:1.This article is based on the calculation method of the elastic properties of the support,which is reflected by the stiffness,and based on this,the stiffness is divided into five gradients to study the effect of its different stiffness on the anti-overturning stability of the curved beam bridge.The results show that the stiffness of the support has a great influence on the anti-overturning stability of the curved girder bridge.The smaller the stiffness,the greater the elasticity of the support,the higher the antioverturning stability coefficient of the bridge.2.Due to the special force relationship of the curved beam bridge,the different stiffnesses of the inner and outer bearings will also have different effects on its antioverturning stability.This paper further studies its stability against overturning by changing the inner and outer stiffness values of the curved beam bridge support The research results indicate that for curved beam bridges,the greater the difference in stiffness values between the inner and outer sides of the curve,the greater the overall stability against overturning compared to the uniform setting of the entire bridge to the same stiffness value.3.After determining the influence of the support stiffness on the stability of the curved beam bridge,the influence of the support layout,the radius of curvature,and the spacing of the supports on the stability of the anti-overturning stability of the curved beam bridge while considering the stiffness of the support was further studied.According to the calculation results,specific prevention and control measures are given to improve the stability of the bridge.4.Overloading is the biggest hidden danger to the safety of urban bridges,and overloading of heavy vehicles is very harmful to the life of the bridge and the safety of vehicles and pedestrians.Therefore,this paper takes the 550 k N standard axle load vehicle as a typical vehicle,and uses curved girder bridges with different curvature radii.Under four different working conditions: single-vehicle crossing,double-vehicle crossing,three-vehicle crossing,and four-vehicle crossing the bridge,the ultimate load values of the single vehicle under the limit state of normal use and the ultimate state of carrying capacity are respectively obtained.Finally,suggestions are given to strictly control overload behavior to avoid bridge disasters.