Abstract

This study presents the Probabilistic Seismic Demand Model (PSDM) and explores optimal intensity measures (IMs) for nuclear power plant (NPP) equipment when subjected to ground motions having high-frequency (HF) and low-frequency (LF) contents. To this end, the PSDM is first constructed in terms of the IM and the corresponding engineering demand parameter, and its outcomes are utilized to select the optimum IMs based on the satisfaction of certain essential properties (i.e., efficiency, practicality, and proficiency). Regarding earthquake excitation, different IMs (i.e., structure-independent and structure-dependent IMs) are studied. The results show that the most appropriate IMs for the seismic performance of the cabinet are velocity spectrum intensity and spectral accelerations for the structure-independent IMs and the structure-dependent IMs, respectively.

Moreover, fragility analysis is performed to assess the vulnerability of NPP equipment. The outcomes indicate that the cabinet is highly vulnerable to HF earthquakes as a consequence of response amplification. In addition, the selection of the earthquake IM has an important influence on the collapse capacity of the cabinet, and the fragility curves obtained from structure-dependent IMs are more reliable in comparison to those of structure-independent IMs.

摘要

本研究提出了概率地震需求模型 (PSDM)，并探讨了核电厂 (NPP) 设备在遭受具有高频 (HF) 和低频 (LF) 内容的地面运动时的最佳强度测量 (IM)。为此，首先根据 IM 和相应的工程需求参数构建 PSDM，并利用其结果根据某些基本属性（即效率、实用性和熟练程度）的满足来选择最佳 IM。关于地震激发，研究了不同的 IM（即结构无关和结构相关的 IM）。结果表明，对于机柜抗震性能最合适的 IM 是结构无关 IM 和结构相关 IM 的速度谱强度和谱加速度，

此外，还进行了脆弱性分析以评估核电厂设备的脆弱性。结果表明，由于响应放大，机柜极易受到高频地震的影响。此外，地震IM的选择对柜体的倒塌能力有重要影响，与结构无关的IM相比，由结构相关的IM获得的脆性曲线更可靠。