A steel-concrete composite cable-stayed bridge features integrated steel girders and concrete decks linked by shear connectors to support loads,but stress concentration in wet joints can lead to cracking.In-situ tests...A steel-concrete composite cable-stayed bridge features integrated steel girders and concrete decks linked by shear connectors to support loads,but stress concentration in wet joints can lead to cracking.In-situ tests were conducted on key sections of steel-concrete composite cable-stayed bridges to analyze the stress-strain evolution of wet joints under environmental factors,constraints,and complex construction processes.The coordinated working performance of the bridge decks was also analyzed.The results indicate that temperature is the key factor affecting the stresses and strains in wet joint concrete.Approximately 7 days after casting the wet joint concrete,the strains at each measurement point of the wet joint are approximately negatively correlated with the temperature change at the measurement point.Different locations within the wet joints have respective impacts,presenting potential weak points.Construction conditions have a certain impact on the stress and strain of the wet joint.The top deck of the steel box girder is not fully bonded to the bottom surface of the wet joints,resulting in a certain strain difference after loading.To further analyze the cooperative working performance of steel box girders and concrete wet joint bridge deck systems,finite element analysis was conducted on composite girder structures.A stiffness calculation method for shear connectors based on numerical simulation was proposed.The results indicate that strain differences can cause interface slip in composite girders.This slip leads to increased deflection of the composite girders and increased tensile stress in the bottom plate of the steel box girders.This study clarifies the stress conditions and factors affecting wet joints during construction,preventing early cracking,and offers precise data for a full bridge finite element model.展开更多
文摘A steel-concrete composite cable-stayed bridge features integrated steel girders and concrete decks linked by shear connectors to support loads,but stress concentration in wet joints can lead to cracking.In-situ tests were conducted on key sections of steel-concrete composite cable-stayed bridges to analyze the stress-strain evolution of wet joints under environmental factors,constraints,and complex construction processes.The coordinated working performance of the bridge decks was also analyzed.The results indicate that temperature is the key factor affecting the stresses and strains in wet joint concrete.Approximately 7 days after casting the wet joint concrete,the strains at each measurement point of the wet joint are approximately negatively correlated with the temperature change at the measurement point.Different locations within the wet joints have respective impacts,presenting potential weak points.Construction conditions have a certain impact on the stress and strain of the wet joint.The top deck of the steel box girder is not fully bonded to the bottom surface of the wet joints,resulting in a certain strain difference after loading.To further analyze the cooperative working performance of steel box girders and concrete wet joint bridge deck systems,finite element analysis was conducted on composite girder structures.A stiffness calculation method for shear connectors based on numerical simulation was proposed.The results indicate that strain differences can cause interface slip in composite girders.This slip leads to increased deflection of the composite girders and increased tensile stress in the bottom plate of the steel box girders.This study clarifies the stress conditions and factors affecting wet joints during construction,preventing early cracking,and offers precise data for a full bridge finite element model.
