Extended deterministic seismic hazard assessment for the Aswan High Dam, Egypt, with emphasis on associated uncertainty

Abstract

The Aswan High Dam is one of the largest civil structures of the 20th century in the world. Earthquake risk reduction studies on this structure have been an important ongoing socioeconomic concern. Seismic hazard assessment for the Aswan High Dam is performed through an extended deterministic approach with particular attention to the uncertainty analysis applying a recently developed method. The input data set consists of all the available reasonable seismotectonic models, maximum magnitudes and attenuation models that yielded a total of 96 scenarios. We select two desired exceedance probabilities (10 and 20%) that any of the 96 scenarios may exceed the largest median ground acceleration. The largest median ground acceleration is found to be 151 cm s−2. The ground motion was calculated at 5th, 16th, 50th, 84th and 95th percentile levels for both selected probabilities of exceeding the median peak ground acceleration. 5% damping median response spectra are provided for the dam site based upon a stochastic simulation technique and on borrowed attenuation relationships. There are a few seismic hazard studies (probabilistic and deterministic); however, this is the first study that aims at producing a seismic hazard evaluation for such an important site in the region with emphasis on the associated uncertainties.