Seismic Site Response Characterization for Suez Canal Region, Egypt

The Suez Canal Economic Zone (SCZone) is a mega project in Egypt that was launched to increase the role of the Suez Canal region in international trading and to develop the urbanization of the region. The reliable assessment of seismic hazard is a crucial input information for the designer and planner of all projects in this area. In this study, an updated seismic hazard map for Suez Canal region that incorporates revised historical earthquake catalogs, morphostructural zonation data (MZ), revised focal mechanism solutions and mechanical models of the lithospheric structure is provided. This is done within the framework of the Neo-Deterministic Seismic Hazard Assessment (NDSHA) procedure that may efficiently incorporate earthquake source rupture data, geological information and any reliable new information to adequately compute the earthquake ground motion maps, like PGA, PGV and PGD. This methodology provides a comprehensive source of ground motion records (acceleration, velocity, displacement) for Egypt where a substantial challenge is posed by the lack of recorded data. To consistently assess the uncertainty of our understanding of the seismic hazard and its effect on critical structures a sensitivity analysis is performed varying, for example, (a) source focal mechanism, (b) directivity (c) rupture process and (d) seismotectonic model. Starting from the initial definition of the source, bedrock and site properties based on the available knowledge of the characteristics of the different earthquake scenarios and of the soil structural properties of the area deduced from the ambient noise array measurements, a set of ground shaking scenarios have been computed at the selected profile crossing the Suez Canal. Variations of the ground shaking scenarios are evaluated looking basically at: (a) the amplitudes measured on the waveforms and the response spectra, (b) the changes in the shaking duration and (c) the modifications in the amplification patterns. Finally, the seismic input (e.g. response spectra, time histories) at the tunnel site that undergoes the Suez Canal to connect Sinai peninsula with the western side of the country is provided.