Abstract

Cable-stayed bridges have been constructed with different type of towers (pylons) in the World, namely H-shaped, A-shaped, inverted Y-shaped, single column, diamond-shaped. More than half of the cable-stayed bridges utilised the towers with inclined legs. The dynamic response of inclined tower legs can be extremely complicated during earthquakes. Real earthquakes provide an excellent opportunity to gain insight into the performance of the towers. The present paper focuses on the real dynamic responses of inverted Y-shaped towers in long span cable-stayed bridges by using monitoring data recorded during moderate earthquakes. Nissibi cable-stayed bridge with two inverted Y-shaped towers constructed in Adıyaman, Turkey is selected for the application. Samsat (Adıyaman) earthquake with magnitude 5.5 (Mw) occurred near the bridge site. The dynamic responses of the bridge towers during the earthquake have been recorded using 3 D accelerometers. Vertical and horizontal spatial variations of the acceleration responses recorded during the earthquake at the foundation, deck and top levels of the two towers in longitudinal, transverse and vertical directions are evaluated and compared with each other. Significantly acceleration amplifications along the height of the towers and arrival time delays between the tower foundations are observed on the selected cable-stayed bridge.

摘要

斜拉桥在世界上已经建造了不同类型的塔（塔），即H形，A形，倒Y形，单柱，菱形。一半以上的斜拉桥采用斜拉桥塔。地震期间倾斜塔腿的动态响应可能极其复杂。真实的地震提供了一个极好的机会来深入了解塔的性能。本文利用中等地震期间记录的监测数据，重点研究大跨度斜拉桥中倒 Y 形塔的真实动力响应。选择在土耳其阿德亚曼建造的具有两个倒 Y 形塔的 Nissibi 斜拉桥进行应用。5.5 级 (Mw) 的萨姆萨特 (Adıyaman) 地震发生在桥址附近。使用 3D 加速度计记录了地震期间桥塔的动态响应。评估地震期间两座塔的地基、甲板和顶层在纵向、横向和垂直方向上记录的加速度响应的垂直和水平空间变化，并相互比较。在选定的斜拉桥上观察到沿塔高的显着加速度放大和塔基之间的到达时间延迟。评估横向和垂直方向并相互比较。在选定的斜拉桥上观察到沿塔高的显着加速度放大和塔基之间的到达时间延迟。评估横向和垂直方向并相互比较。在选定的斜拉桥上观察到沿塔高的显着加速度放大和塔基之间的到达时间延迟。