Damascus is located at the southern part of Syria not far from the Dead sea
fault system, in particular from one of its branches the Sergayah fault. The
latter in particular is a quite active fault system and the main seismic source for
both destr
uctive historical events felt and instrumental seismicity recorded in
Damascus. To model seismic ground motion in Damascus plain and to estimate
its amplifications we use a 2-D hybrid method coupling modal summation with
finite differences. This techniques allows to compute ground motion in
laterally heterogeneous an elastic media. Synthetic seismograms with a cutoff
frequency of 5 Hz are created along one 2-D profile passing through the city of
Damascus for possible seismic source with assumed magnitudes around 6.5
located on the Sergayah fault. The average regional structural model and the
laterally heterogeneous parts of the profiles have been derived from detailed
geological and geotechnical data available for the investigated area. From the
computations we can infer that the maximum ground motion amplification
values in Damascus plain are generally found at frequencies around 1 Hz and 4
Hz. In addition for assessing liquefaction potential in Damascus plain tow
methods have been used. first one evaluated roughly liquefaction potential
based on topographical and geological information and the second one based on
geotechnical data such as N- value, grain size and estimated peak ground
acceleration to calculate a liquefaction resistance factor, FL. and liquefaction
potential index, IL. We found that IL exceeds 15 which mean probable sever
liquefaction.
