Earthquake engineering needs and seismic hazard assessment

Abstract

We present a detailed discussion on the needs of hazard assessment for different applications of earthquake engineering and risk assessment. This discussion includes design and risk assessment issues. We define the requested information from seismic hazard analysis as an input to a meaningful and economical engineering analysis. This provides the basis for a detailed review of the main methods of contemporary seismic hazard analysis: (1) traditional Probabilistic Seismic Hazard Analysis (PSHA) as used in building codes of many countries, (2) scenario-based seismic hazard analysis or neo-deterministic seismic hazard analysis (NDSHA) as the principal alternative, and (3) the state of the art physics-based deterministic method.We demonstrate that only the physics-and scenario-based seismic hazard analysis method that combines (a) contemporary seismic waveform modelling, (b) an in-depth geological and seismo-tectonic analysis of the region of interest, and (c) empirical information is able to provide the complete set of input information for economical earthquake engineering analysis that allows to combine improved seismic performance of both the structures and components with reasonable design costs. We show that the scenario-based seismic hazard method can easily be adapted/extended for risk assessment as required in assurance applications by developing state of the art probabilistic data models that are in compliance with observational data assembled in earthquake catalogues.The paper includes a practical example of the scenario-based approach for the development of the design basis of a critical infrastructure and the risk assessment for a seismically induced production loss of a nuclear power plant located in Switzerland.We recommend that DSHA and NDSHA must be used for engineering design. When/if PSHA is required based on national regulations, it is highly recommended to compare the results/output of PSHA results with that of physics-and scenario-based analysis or NDSHA maps.

Towards damage-consistent performance-based design of critical infrastructures

“…parameters. Both probabilistic and traditional deterministic seismic hazard analysis do not provide the full level of information needed by engineers as long as they are focussing on simple ground motion parameters [6].…”

“…A realistic performance-based design is only possible if the seismic hazard assessment is performed in parameters that are closely linked to the physical damage in earthquakes. The only hazard parameter that is directly connected to the physical effects of earthquakes and that is used in seismic hazard assessment is intensity [6]. The intensity scale EMS-98 [10] is directly linked to the physical effects of earthquakes.…”