Basis for the determination of waveforms for the sites of dams in Switzerland – Subproject 1: Disaggregation of seismic hazard for return periods of 1000, 5000, 10000 years

Abstract

This report documents part 1 of the project “Basis for the determination of waveforms for the sites of dams in Switzerland”, commissioned by the Swiss Federal Office of Energy (SFOE). The first part of the project deals with the disaggregation of ground shaking hazard levels for mean return periods of 1000, 5000, 10000 years and three intensity measure types: peak ground acceleration (PGA), spectral acceleration at 0.15 s period (SA(0.15s)) and 1.0 s period (SA(1.0s)). This report briefly describes the seismic hazard model employed as source for the disaggregation (SUIhaz15), the disaggregation processing, the final results produced for every geographical node of the disaggregation grid, and the results obtained by gathering such nodes by SIA 261 seismic zone. The main results from the disaggregation of the ground shaking levels described by the three-intensity measure types are also combined – at the level of each disaggregation node and SIA zone as well – to assess the contribution to exceedance of the full UHS of various magnitude – distance scenarios. The numerical results of the disaggregation analysis are contained in an electronic supplement attached to this report.