【摘要】 圆端形实体桥墩在高速铁路中广泛使用,有纵横方向长度比大,纵筋率较小等特点,目前该类桥墩已有的试验缺乏系统性和完善性,其抗震性能研究还不够充分。以当前高速铁路中常见的圆端形截面桥墩为原型,根据模型相似理论,改变影响抗震性能主要因素的设计变量,按正交试验设计方法,设计9根桥墩缩尺模型。在考虑恒定轴向力的作用下,进行低周反复荷载试验,得到不同桥墩模型的破坏特性、滞回曲线,依此分析各因素水平下桥墩的延性、耗能性能、刚度与强度退化规律。通过试验回归分析,比较分析剪跨比、轴压比、纵筋率与体积配箍率等4个因素对延性性能的影响程度。试验结果表明,纵筋率较低的圆端形实体桥墩的滞回曲线呈显著的捏缩状,轴压比和纵筋率的提高都将使桥墩的延性减小,而剪跨比与体积配箍率对延性影响较小。当纵筋率较低时桥墩的耗能性能较差,而提高纵筋率能够显著提高桥墩的耗能性能。更多还原

【Abstract】 Solid piers with round ended cross-section are widely used in China high-speed railway.Bridge piers of this type have relatively high aspect ratio and low longitudinal reinforcement ratio.Existing experiments are not systematic and sufficient,so the seismic performance of this type of pier is still not understood enough.Derived from the prototype of round-ended piers in high-speed railway,nine large scale model piers were designed according to the model similitude theory.The orthogonal experiment method was used to consider the different design variables which can affect the seismic behaviors.The failure characteristics,hysteresis curves and skeleton curves were obtained based on cyclic loading tests considering axial load,and then the influence of each variable on the displacement ductility,energy dissipation,strength and stiffness degradation of the piers were analyzed.The main factors affecting ductility,including the axial compression ratio,the longitudinal reinforcement ratio and the volume-stirrup ratio were discussed.It is found that the hysteresis curves have significant pinch in the models with low reinforcement ratio.The displacement ductility decreases with the axial load ratio and longitudinal reinforcement ratio,while the volume-stirrup ratio and shear span ratio have little effect on the ductility.The energy dissipation ability is poor when the longitudinal reinforcement ratio of the piers is relatively low,while the energy dissipation performace can be significantly improved by increasing the longitudinal reinforcement ratios.更多还原