الفهرس 
Acknowledgements
Effects of different wave types on the H/V ratioOnly 14 pages are availabe for public view
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Abstract
The geology at Kottamiya, Rehab City and Zahraa-Madinat-Nasr to the East of Cairo
(Egypt) is composed of low-velocity sediments on top of a rigid rock basement. Such
sediments include the loose sands of the Gebel Ahmar formation, marl and shale of
Maadi formation, in addition to sparse quaternary soil covers. Due to the contrast of
the seismic impedance to the underlying bedrock, these soft sediments have the
potential of amplifying the ground motion of an earthquake considerably.
For the evaluation of seismic hazard, we computed the seismic site response in these
areas by developing one-dimensional velocity models and average seismic velocities,
including Vs30. To do that, we applied different techniques including the horizontal
to vertical Fourier spectral ratio of ambient vibration recordings (H/V) and multichannel analysis of surface waves from active seismic experiments (MASW). The
velocity models are obtained by combined inversion of surface wave dispersion
curves and Rayleigh wave ellipticity functions. The dispersion curves are used to
constrain the shallow low-velocity part of the profile, while the ellipticity of Rayleigh
waves is used to resolve the depth of the bedrock interface. from the obtained
velocity models, the ground-motion amplification is derived by applying 1D
numerical modeling of SH-wave transfer functions. The study reveals that the
different sites experience important frequency-dependent amplification, with largest
amplification occurring at the resonance frequencies of the sites. Amplification up to a
factor of 5 is found, with some variability depending on the soil type (vs30 ranges
between 340 and 415 m/s2) and the resonance frequency. Amplification is expected in
the frequency range that is important for buildings.
The second field of research concerned probabilistic seismic hazard assessment for
the study areas. The earthquake catalogue for Egypt and surrounding areas is revised.
A combination of classical area-sources and active faults are defined to describe the
spatial distribution of the earthquakes. The seismic activity rates are analyzed with
state-of-the-art techniques using the earthquake catalogue. In addition, the seismicity
level is derived by using geodetic strain rates obtained from GPS-derived velocityfields. Moreover, for the active faults, the activity is estimated from the slip rates.
As part of the input preparation for seismic hazard calculation, a suite of adequate
ground-motion prediction equations is selected. After final quality checks of all input
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data, probabilistic seismic hazard computation is performed with the software
Openquake considering the inherent uncertainties at all levels of model building and
analysis. The PGA for 10% probability of exceedance is in the range 165-170 cm/s2 at
Kottamiya, 170 to 180 cm/s2 at Rehab City and about 167 cm/s2 at Zahraa. A small
spatial variability in PGA is observed and is mainly related to changes in the soil
properties in the near surface layers.