Movement Mechanism Analysis Of Concrete Curved Girder Bridges Under Coupled Multi-factor Actions

With the development of high-grade highway and the construction of urban interchange hub in our country,the curved beam bridge has been more and more widely applied and developed due to its better adaptability and aesthetics.In recent years,it has been found that during operation stage some curved bridges encounter the problem of bridge movement.The.movement of the curved girder bridge can lead tothe malfunction of some parts of the bridge,such as the tearing of the expansion joints;the dislocation of the railings,the cracking of bridge piers and abutments,the support uplift,the overturning of the girder,and ultimately cause,traffic accident.Therefore,based on the real bridge,this paper studies the movement mechanism of concrete curved girder bridges.The main research contents and achievements of this paper are as follows:(1)The bridge movement rating factor M is defined to quantify the influence of each influencing factor on the radial and tangential displacements of reinforcedconcrete curved girder bridges and prestressed concrete curved girder bridges.(2).The finite element models of 115 continuous concrete curved box girder bridges are established to analyze the effects of internal factors including radius of curvature,span length,bearing arrangement,prestress and external factors including self-weight load,homogeneous temperature variation,temperature gradient,shrinkage and creep of concrete,lane effect,centrifugal force,braking force on the radial and tangential movement of the bridge.The results show that:the bearing arrangement,the radius of curvature,the temperature rise,the shrinkage and creep effect of concrete and the centrifugal force are the most important factors that cause the bridge movement;while the braking force mainly causes the tangential displacement and has little effect on the radial movement;under different load conditions,the effect of pier height on the creep has no specific regularity;the lane effect indirectly affects the bridge movement mainly by affecting the distribution of vertical support forces;vehicular overloading affects bridge movement greatly,so this should not be ignored by designer.(3)The main internal factors and load factors that affect the bridge movement of the curved girder bridges are analyzed by orthogonal numerical simulation respectively.Among the internal factors,the bearing arrangement pattern is the most sensitive factor to the bridge movement;The radius of curvature and the span are of less effect.Among the load factors,the system temperature is the most sensitive factor when the radius is small,however,for the case of large radius of curvature,the most sensitive factor is centrifugal force.