Resilience-based seismic design theory and methodology for urban area

With the accelerated advancement of global urbanization, the demand for urban earthquake risk prevention and mitigation has become increasingly pronounced. This growing demand poses significant challenges to traditional seismic design theories that focus primarily on the seismic safety of engineering structures. At present, systematic methodologies for resilience-based urban seismic design remain largely undeveloped both domestically and internationally. This paper reviews the evolution of seismic design theory. The fundamental connotation of urban seismic resilience is clarified. A resilience-based urban seismic design framework is proposed. The framework follows the principle of “one foundation and two safeguards.” Engineering resilience serves as the foundation. Institutional resilience and socio-economic resilience provide essential support. Three design objectives are defined. The first objective is to ensure the seismic safety of buildings and civil infrastructure. The second objective is to satisfy prescribed post-earthquake functionality of urban systems. The third objective is to enable rapid post-earthquake recovery. A five-step urban seismic resilience design procedure is established. The first step is the determination of urban seismic resilience targets. The second step is structural seismic safety design of buildings and civil infrastructure. The third step is post-earthquake functionality assessment of urban engineering systems. The fourth step is the development of technologies and strategies for rapid functional recovery. The fifth step is conceptual design of institutional and socio-economic seismic resilience. The proposed procedure enables coordinated design across buildings and civil infrastructure, engineering systems, and urban systems. Coordination is achieved in resilience objectives, post-earthquake functionality, and recovery processes. A theoretical system and methodological framework for resilience-based urban seismic design are established. The relationship between resilience-based seismic design for and performance-based seismic design for structures is clarified. The proposed methodology supports a shift in disaster-prevention practice. The focus moves from structural seismic safety to post-earthquake functionality and rapid recovery at the system and urban levels. This methodology provides theoretical and technical support for earthquake-safe and resilient cities.