This discussion is based on the paper by Pang et al. (2020) (hereafter identified as “the original authors” and “the original paper” or “the reference paper”). The original authors employed the endurance time analysis (ETA) and incremental dynamic analysis (IDA) techniques to investigate the probabilistic response of a deep water bridge in a reservoir. They derived multiple fragility curves using both techniques. Derivation of ETA-based fragility functions in the original paper is not fully consistent with the nature of seismic fragility curves. The underpinning concept of fragility curves is tied with ground motion record-to-record (RTR) variability, while the conventional ETA does not offer such an ability. We discussed several underlying assumptions in the ETA method, as well as different sources of ground motion RTR variability (from IDA technique) which may affect the logarithmic dispersion in a fragility curve (and it is unseen in conventional ETA method).

该讨论基于Pang等人的论文。（2020年）（以下简称“原作者”和“原论文”或“参考论文”）。原始作者采用耐久时间分析（ETA）和增量动力分析（IDA）技术来研究水库中深水桥的概率响应。他们使用这两种技术得出了多个脆性曲线。原始论文中基于ETA的脆性函数的推导与地震脆性曲线的性质并不完全一致。易碎性曲线的基本概念与地面运动记录到记录（RTR）的可变性相关联，而常规的ETA不提供这种功能。我们讨论了ETA方法中的几个基本假设，