چكيده لاتين :
The complete microzonation and site response studies
require the characterization of subsurface materials considering
local subsurface profiles of the site or region. The general site
characterization comprises of the evaluation of subsurface features,
material types, material properties and buried/hollow structures, by
which it is determined whether the site is safe against earthquake
effects. In this study, an attempt has been made to characterize the
Bangalore Mahanagar Palike (BMP) area of about 220km2 using the
shallow geophysical method, Multichannel Analysis of Surface wave
(MASW), which identifies each type of seismic wave on a multichannel
record using the refraction survey and produces shear-wave velocity
(Vs) profiles. The study area of BMP has been characterized as per
NEHRP (National Earthquake Hazards Reduction Program) and IBC
(International Building Code) site classification using an average
shear wave velocity (Vs30) of 30m, obtained from MASW. In the study
area, 58 one-dimensional (1-D) MASW survey has been carried out and
respective velocity profiles are obtained. The major part of the BMP
area can be classified as "site class D", and "site class C" and a smaller
part in and around Lalbagh Park is classified as" site class B". Further
site response has been carried out using measured shear wave velocity
and synthetic ground motion developed by Sitharam and Anbazhagan
[11]. Site response study shows that due to soil condition, large
modification of wave amplitudes are observed resulting in higher peak
ground acceleration when compared to rock level acceleration.
