Mechanical Property Analysis Of Curved Girder Bridge And Optimal Design Of Bearing

Curved girder bridge with its flexible line-type, beautiful appearance, good driving condition, and many other advantages has become an indispensable bridge type in modern traffic engineering.Curved girder bridge has been widely used in urban overpass, highway overpass, approach roads and mountain roads. In order to meet the demand of growing traffic in China, more and more curved girder bridges will be built. However, in recent years, engineering accidents of the curved girder bridge often occur in our country, and there is no specification related to the design of curved girder bridge in our country. Therefore, further study of curved girder bridge is necessary.In view of this, the following work is done in this article:1) Temperature gradient for curved girder bridge is introduced in this artic le. To ensure the security of curved girder bridge under the effect of temperat ure gradient, both vertical temperature gradient and horizontal temperature gra-dient are recommended to be considered in the calculation of response of cur-ved girder bridge under the effect of temperature gradient.2) The mechanical response of curved girder bridge models under various static load force is analyzed by finite element method, and the bridge models are supported by different support system. It is found that, due to the curved girder bridge's unique coupling effect of moment and torque, curved girder bridge under the effect of the vertical load, prestressed load and vertical temperature gradient will have great torque moment, and the values of the torque moment produced by the three kinds of load are in the same order of magnitude. Because of resisting the torque moment, the inside bearings on the torsion bearing pier are easily leaded to negative reactions, thus cause engineering accident. Integral temperature rise and horizontal temperature gradient will cause the bearings'comparative great horizontal shear force. Finally, it is found that all-torsion-bearing support system for curved bridge is not the best support system. Therefore, choosing appropriate torsion-bearing-span and setting single hinged bearing is good for curved girder bridge.3) Eccentricity of the curved girder bridge's bearings is discussed. Author successfully apply Powell method to the calculation of optimal eccentricity of the single hinged bearing, and raise a method to calculate the eccentricity of torsion bearing. Finally, author develop program to calculate the value of eccentricity of curved girder bridge's bearings by C# language, which has some practical value.4) Seismic analysis for curved bridge is taken by mode-superposition response spectrum method. It is found that, the superstructure's internal force and the bearings' vertical reaction of curved girder bridge are less than that of straight girder bridge; however bearings'horizontal shear force of curved girder bridge is greater than that of straight girder bridge.