Abstract

When a cable-stayed bridge is subjected to strong ground motions during an earthquake, the vibration of the tower column is much stronger and more severe in the transverse direction than the longitudinal direction, due to the lateral restriction between the tower and the main girder. To address this issue, the current seismic design of cable-stayed bridge recommends that a larger reinforcement ratio in tower column be used to achieve the target seismic performance (i.e., remaining elastic). This entails an increased number of the piles and the reinforcement volume as well and thus such a design is often not cost-effective. Alternatively, the tower column can be designed to have allowable ductile behaviour for saving costs. Therefore, this study aimed to verify the ductility margin and the allowable ductile performance of the H-shaped concrete tower, by studying its lateral elastic-plastic behaviour and damage mechanism through incremental dynamic analysis, and its limited ductility against the lateral inertial forces based on quasi-static test.

摘要

斜拉桥在地震中受到强烈的地震动时，由于塔与主梁之间的横向限制，塔柱在横向上的振动比纵向上强得多，也更剧烈。针对这一问题，目前斜拉桥的抗震设计建议采用较大的塔柱配筋率，以达到目标抗震性能（即保持弹性）。这需要增加桩的数量和加固体积，因此这种设计通常不具有成本效益。或者，可以将塔柱设计为具有可允许的延展性以节省成本。所以，