UHPC空心墩滞回加载开裂模式和抗震性能试验研究OA

Ultra-high performance concrete(UHPC),characterized by its high strength and light self-weight,has attracted increasing attention in bridge engineering in recent years and has been applied in demonstration projects.In this study,the concept of replacing conventional concrete bridge piers with UHPC hollow piers was proposed.Quasi-static tests were conducted on three UHPC circular hollow pier specimens and one con-ventional concrete circular hollow pier specimen for comparison.Regarding the cracking pattern and mecha-nism of circular hollow piers,the principal stress trajectories under lateral loading were presented for the first time,and a formula for calculating the principal tensile stress was derived,revealing the crack propagation be-havior of such piers.The experimental results indicate that UHPC hollow piers exhibit superior lateral strength,higher stiffness,and greater energy dissipation capacity.Their structural performance is significantly influenced by the reinforcement ratio and wall thickness.Based on the hysteretic response,the seismic perfor-mance of UHPC hollow piers is further evaluated.Material strength and wall thickness of hollow pier have a significant effect on stiffness,while the influence of reinforcement ratio is relatively limited.However,a low reinforcement ratio leads to a reduced ductility.UHPC circular hollow piers represent a promising alternative to conventional concrete bridge piers.