耗能防撞装置在桥墩基底摇摆隔震中的性能研究

在桩基桥墩基底摇摆隔震中，提出一种增加柔性耗能防撞装置设计方案。当罕遇地震发生时，桥墩在与基础分离处发生摇摆，与设计的防撞装置发生碰撞，延长了系统的撞击时间，使撞击力下降。利用多个钢绳柔性防撞圈同期作用的动态有限元方法建立模型，对防护围刚度分三种情况进行讨论，发现在撞击防撞装置的过程中，前期为部分防撞圈发挥作用，后期为全部防撞圈发挥作用，且“同期作用历时”越短越好。分析结果表明，降低防撞构件的初始刚度，可延迟最大撞击时间，同时可减小最大的撞击压力。

Study on Performance of Energy-Consuming Anticollision Device in Pier Base Swing Isolation

In relation to swing isolation for pier base of pile foundation, a design proposal of anticollision device was put forward to increase flexible energy consumption. When a severe earthquake attacks, swing arises at the position where pier separates from foundation. This will lead to collision with the designed anticollision device, thus to extension of collision time of the system and reduction of impact force. By means of dynamic FEM for simultaneous action of multiple steel-wire-rope loops, a model was established to discuss stiffness of the loops in three cases. It was found out that, during the collision with the anticollision device, only a part of the loops played a role in the earlier stage, while all of the loops in the later stage; moreover, the shorter ＂the duration up to simultaneous action＂, the better. The study result shows that decrease of initial stiffness of anticollision device may delay maximum collision time and reduce maximum impact pressure.