Seismic Risk Analysis of Critical Engineering Structures

地震是破坏性最大的自然灾害之一。由于近几十年来发生了多次破坏性地震，关键工程结构的地震危险性分析已成为地震工程学中最重要和最热门的课题之一。世界各地的核能行业正在发起一场史无前例的、广泛的对地震危害和核电站系统风险的重新评估。此外，核能监管机构和公用事业公司正在认真审查现有的估计核电厂地震风险的方法。在现有的地震危险性分析方法中，人们认识到了一些不足之处。这项研究的目的是开发一个现代地震危险性分析的概率框架。这将包括通过对初级和次级结构的响应分析、对关键工程结构系统的矢量值地震易损性和风险分析，制定与矢量值概率地震危险性分析一致的新的设计谱。这项研究将研究新开发的矢量值统一危险谱(VUHS)的谱形状，以进一步改进其生成，并校准VUHS的地震危险等级，以便在抗震设计规范中实施。为分析土-结构相互作用，将开发用于模拟空间变化的土属性的综合随机场模型和合成空间变化的地面运动的方法。这项研究将发展以关键地震动参数为基础的矢量值地震易损性分析和矢量值地震危险性分析，以提供更严格和准确的关键工程结构的地震危险性评估。这种基于向量值分析的框架将极大地改进抗震设计规范。开发的方法可用于设计新的和评估现有的关键工程结构，以符合现代地震安全标准。

Earthquake is one of the most destructive natural disasters. Since several destructive earthquakes have occurred in recent decades, seismic risk analysis for critical engineering structures has become one of the most important and popular topics in earthquake engineering. Nuclear energy industries world-wide are launching an unprecedented and extensive re-evaluation of seismic hazards and risk to nuclear power plant (NPP) systems. Furthermore, nuclear energy regulators and utilities are taking a critical look at the existing methods of estimating seismic risk of NPPs. A number of shortcomings have been recognized in the existing methods of seismic risk analysis. The objective of this research is to develop a modern probabilistic framework of seismic risk analysis. This would include development of a new design spectrum consistent with vector-valued probabilistic seismic hazard analysis, through the response analysis of primary and secondary structures, to the vector-valued seismic fragility and risk analyses of critical engineering structural systems. The proposed research will study the spectral shape of a newly developed vector-valued uniform hazard spectrum (VUHS) to further improve on its generation, and to calibrate the seismic hazard level of the VUHS so that it can be implemented in seismic design codes. Comprehensive random field models to model spatially varying soil properties and approaches to synthesize spatially varying ground motions will be developed for soil-structure interaction analysis. The proposed research will develop vector-valued seismic fragility analysis and vector-valued seismic risk analysis, in terms of vectors of key ground motion parameters, to provide more rigorous and accurate seismic risk estimations of critical engineering structures. This framework based on vector-valued analysis will substantially improve seismic design codes. The methodologies developed can be used to design new and to assess existing critical engineering structures to comply with modern standards for seismic safety.