Abstract:
For accomplishing comprehensive regional seismic damage assessment, Geographical
Information System (GIS) provides a perfect environment, GIS has the capability to
store, manipulate, analyze and display the large amount of required spatial and tabular
data. This study intends to carry out regional seismIc damage assessment for the
Rajshahi City using geographic Information system. where reflection of ground
shaking and the secondary site attnbutes of soil amplificalion and liquefaclion are the
salient features The melhod to combine the different hazards is based on a weighted
average applORch A soil database from 50 boreholes was used to develop site
amplification and soil liquefaction potential maps ufthe study area. Bolh of these site
effects are integrated in Geographical Information System platfonn for combined
hazard assessment, Three past historical earthquakes were assessed as scenario events
namely the 1885 ~engal earthquake, the 1897 Greallndian earthquake and the 1930
Dhubri earthquake, Intensily value obtained for these events is' calibrated against
attenuation laws to check the applicability ofthe laws for the study. Finally, the Great
Indian Earthquake of 1897, with the attenuation law of McGuire (1978) was chosen as
the scenario earthquake. as it shows highest bed lOck PGA (0,06340) PGA value is
converted into },ill] values to integrate the effect of site amplification as well as
liquefaction and then combined hazard map is proposed for this study area, Only for
ground shaking, approximately II percent buildings are ~1;imated to be damaged,
Again for ground shaking and liquefaction, approximately 15 percent buildings are
estimated to be damaged Some major critical facilities are idelllified that are the most
vulnerable as they fall under VIIl-MM]! EMS Intensity hazard zone. Based on soil
(natural) frequency some zones are suggested for building height restrictions using
thumb rules, According to soil liquefaction analysis particular zones are identified
where groL1ndimprovement is suggested,
