Study On Crawling Behavior Of Small Radius Curved Steel-concrete Composite Beam Bridge

The Curved Steel-Concrete Composite Girder Bridge is widely used in urban interchange and ramp bridge due to its beautiful shape,flexible linear layout and small floor area.The curved steel-concrete composite continuous girder bridge has become a necessary means to realize traffic connection in different directions.With the increasing number of Curved SteelConcrete Composite Continuous Girder Bridges,the " crawling" of curved girder bridges often occurs,endangering the safety of the bridge structure,so it is of great significance to carry out the research on crawling and countermeasures of Curved Steel-Concrete Composite Girder Bridges.The main contents of this paper are as follows:(1)By using the methods of formula derivation and mechanical analysis,the mechanical properties and the generation of creepage of the Curved Steel-Concrete Composite Continuous Girder Bridge are preliminarily studied.The factors influencing the "active crawling" and "passive crawling" of the Curved Steel-Concrete Composite Continuous Girder Bridge are put forward.(2)Based on the actual Curved Steel-Concrete Composite Continuous Beam Bridge with small radius curve,the ANSYS finite element model is established considering the relative slip of the steel beam and the concrete bridge panel interface.By comparing the empirical formula calculation and literature data with the finite element analysis data,the correctness of the details processing of the ANSYS finite element model of the Curved Steel-Concrete Composite Beam Bridge established in this paper is verified,which lays the foundation for the subsequent finite element analysis of the crawling of the curved steel-concrete composite continuous beam.(3)The influence of constant load,system temperature difference,temperature gradient,automobile load centrifugal force and radius of curvature,support system and eccentricity of support on the internal force and deformation of curved beam is analyzed.The overall cooling of the system and automobile load centrifugal force are the main factor affecting the "passive crawling" of the beam,and the radius of curvature is the main factor affecting the "active crawling" of the beam.The smaller the radius of curvature,the radial displacement and torsion of the beam The more obvious the deformation is,the more favorable the whole stability of the bridge structure is.The setting of a certain eccentricity to the outside of the support can effectively reduce the crawling of the curved beam.(4)According to the factors affecting the crawling behavior of the curved beam bridges,put forward corresponding preventive and strengthening countermeasures.The preventive measures include increasing the radius of curvature,adopting a proper support system,setting the pre-eccentricity of the support,and setting a lateral limit device etc.The reinforcement measures include the restoration of the beam and the replacement of the support etc.Finally,the actual bridge model is used to simulate the application of various preventive measures,which further verifies the effectiveness of preventive measures to inhibit the crawling behavior of the curved composite beams.