Abstract

This paper presents the assessment of historic seismic bridge performance of the New Zealand highway bridge stock from the 1968 Inangahua earthquake through to the 2016 Kaikōura earthquake. Spatial ground motion details based on recorded and observed ground motion intensities were used to estimate the peak ground acceleration (PGA), as a measure of the seismic demand at each bridge location. Across all events, a PGA of 0.05 g or higher was experienced on over 800 occasions across bridge sites. Damage characteristics were collated from available literature, with the majority of the highway bridges experiencing either no damage or only minor damage across all the events. At PGAs greater than 0.5 g, the number of bridges with moderate and major damage was still relatively small. There were also no apparent differences between the performance of bridges across the different design eras, despite the varied design and construction practices. Some shorter bridges may have performed better than expected due to the effect of abutment stiffness and damping, while some longer bridges may have performed well due to travelling wave effects. These findings will inform future assessment methods and design, and the accuracy of analytical modelling of the bridge stock.

摘要

本文介绍了从1968年的Inangahua地震到2016年的Kaikōura地震，对新西兰高速公路桥梁桩的历史地震桥性能的评估。基于记录的和观察到的地震动强度的空间地震动细节用于估计峰值地面加速度（PGA），作为每个桥梁位置的地震需求的量度。在所有事件中，跨桥梁站点经历了800多次PGA为0.05 g或更高。损坏特征是根据现有文献整理得出的，大多数公路桥梁在所有事件中都没有损坏或只有很小的损坏。当PGA大于0.5 g时，具有中度和严重损坏的桥的数量仍然相对较少。尽管设计和施工方法各不相同，但跨不同设计时代的桥梁性能之间也没有明显差异。由于桥基刚度和阻尼的影响，一些较短的桥可能会比预期的表现更好，而由于行波效应，一些较长的桥可能会表现良好。这些发现将为将来的评估方法和设计以及桥架分析建模的准确性提供信息。