Overview
ISO/TR 18961:2025 - Buildings and civil engineering works - Seismic resilience assessment and strategies - is a technical report that compiles typical existing information on the concept, assessment and strategies for seismic resilience of buildings and civil engineering works. It is an indexed resource (non‑normative) that summarizes assessment frameworks, resilience indicators, datasets and practical strategy options for designing and retrofitting assets to improve post‑earthquake recovery.
Key topics and technical content
- Concept of seismic resilience: definition, development history and illustrative case studies (e.g., Christchurch 2011) showing the difference between conventional seismic design and resilience‑focused design.
- Assessment methodology: a two‑step approach - (1) determine seismic response and (2) evaluate resilience indicators. Assessment relies on datasets for hazard, building models and damage states.
- Determining seismic response:
- Earthquake hazard inputs (response spectra, ground motion histories, intensity/scenario/time‑based approaches).
- Building performance models and building seismic damage states derived from fragilities and engineering demand parameters.
- Resilience indicators: methods to assess earthquake‑induced casualties, downtime/recovery time, economic losses, and composite seismic resilience level.
- Seismic resilience datasets: inventories, GIS data, ground motion parameters (e.g., PGA/PGV) and component fragility data used in loss and downtime estimation.
- Strategies:
- Design of built assets: structural and non‑structural design for new buildings; retrofitting techniques for existing assets.
- Design for external hazards: planning for secondary earthquake effects and utilities disruption.
- Examples of assessment tools and procedures summarized in the report: FEMA P‑58 (performance assessment), REDi (extended PACT for downtime/reoccupation), Hazus (community loss modeling), GB/T 38591‑2020, ASCE/SEI 41‑17, NZSEE and JSCE guidance.
Practical applications - who should use it
- Standard setters and policymakers - to align resilience metrics and policy priorities with international practice.
- Asset owners, facility and infrastructure managers - to inventory vulnerability, prioritize retrofits and plan recovery expectations.
- Structural and geotechnical engineers, architects and urban planners - to integrate resilience objectives into design and retrofit decisions.
- Emergency planners and economic analysts - to estimate downtime, casualties and economic loss for preparedness and recovery planning.
- Construction and manufacturing sectors - to guide resilient component selection and implementation strategies.
Related standards and tools
- FEMA P‑58, Hazus, REDi/PACT, GB/T 38591‑2020, ASCE/SEI 41‑17, NZSEE, JSCE, and national guidance referenced in the report. ISO/TR 18961:2025 serves as an informational index to these methods and datasets.
Keywords: ISO/TR 18961:2025, seismic resilience, buildings, civil engineering works, seismic resilience assessment, resilience indicators, earthquake hazard, downtime, economic loss, retrofit strategies, FEMA P‑58, Hazus.