基于CDP模型的装配式双柱桥墩在低周往复加载下的力学性能研究

Study on Mechanical Properties of Prefabricated Two-column SolidPiers with Low Cycle Reciprocal Loading Based on CDP Model

以南京市某改扩建装配式桥梁建设为背景,研究低周往复加载作用下装配式双柱实心桥墩的整体力学性能。利用混凝土塑性损伤模型(CDP)与Clough钢筋模型建立考虑套筒的节段装配桥墩有限元模型,分析装配式桥墩的混凝土损伤、钢筋应力等随加载过程的变化规律。结果表明,灌浆套筒局部加强墩柱刚度,使得混凝土损伤上移;混凝土损伤先出现在墩的顶底部,但首先被压坏的部位位于墩柱中部;墩中部箍筋首先屈服,最终墩顶、底部的纵筋大部分屈服;双柱实心矮墩的滞回曲线较扁,耗能能力较弱。

Based on the prefabricated bridge construction in Nanjing 312 national highway reconstruction project,mechanical properties of the fabricated double column solid pier under low cyclic reciprocating loading were studied.An extension large-scale general FE model was established with CDP and‘Clough’steel bar model included sleeves to investigate the variation of concrete damage and steel stress of the fabricated piers with loading process.The results show that the grouting sleeve partially strengthens the pier column stiffness and causes the concrete damage to move up.The concrete damage first appears at the bottom of the pier,but the first damaged part is located in the middle of the pier column.The stirrups in the middle of the pier yield first,and finally most of the longitudinal bars at the bottom of the pier yield.The hysteretic curve of two-column solid piers is flat and the energy dissipation capacity is weak.