【摘要】 为了研究近断层区铁路高配筋重力式桥墩的抗震性能，以某高原铁路简支梁桥为工程背景，设计并制作缩尺比为1/8的桥墩模型，以3条近断层安评波作为地震动输入，对桥墩模型进行振动台模型试验。探究了桥墩模型在不同强度的近断层地震动下的墩顶加速度、墩顶位移及纵筋应变的地震反应特征，并对桥墩模型的抗震性能进行了评价。结果表明，墩顶水平加速度、墩顶位移及墩顶水平加速度放大系数随地震动强度增大而增大，桥墩中部的加速度放大系数增长速率明显大于墩底；在9度设计地震(PGA=0.40 g)下，墩底混凝土未出现裂缝；在接近9度罕遇地震(PGA=0.55 g)时，墩底仅局部混凝土出现微小裂缝，但墩底纵筋应变值远小于其屈服应变值，纵筋性能未能充分发挥。高配筋重力式桥墩在近断层地震动作用下表现出良好的抗震性能。更多还原

【Abstract】 In order to investigate the seismic performance of railway gravity piers with high reinforcement ratio in near fault ground motions, a 1/8 model pier was designed and fabricated, based on the engineering background of a plateau railway simply supported beam bridge, and three near fault ground motion records were selected as the ground motion input. The model pier was subjected to seismic simulation shaking table test. The top displacement, top acceleration and strain of the longitudinal reinforcement of the model pier under varying intensities of near-fault ground motions were studied and the seismic performance of the bridge pier model was also evaluated. The experimental research shows that the top acceleration, top displacement and the amplification factor of top acceleration increased with the increase of the ground motion intensity. The growth rate in the middle of the pier is significantly higher than that at the bottom of the pier. Under 9 degree design earthquake(PGA=0.40 g), there were no cracks in the concrete at the pier bottom. Under a near 9 degree rare earthquake(PGA=0.55 g), only minor cracks appeared in the concrete at the pier bottom. The strain value of the steel reinforcement was lower than the yield strain value and the performance of the steel reinforcement fails to give full play. Gravity bridge piers with high reinforcement ratios exhibit excellent seismic performance under near fault seismic motion.更多还原