International Journal of Geotechnical Earthquake Engineering, 4(1), 83-101, January-June 2013 83 Copyright © 2013, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. ABSTRACT In this study, one dimensional equivalent–linear ground response analyses were performed for some typical sites in the Guwahati city, India. Six bore locations covering about 250 km 2 area of the city were considered for the analyses. As the strong motion signifcantly infuences the ground response, seven different recorded ground motions, varying in magnitude (6.1 to 8.1) and other ground motion parameters, were adopted. Seismic site analyses were carried out for all layers of borelogs using all the seven earthquakes. Results are presented in terms of surface acceleration histories, strain and shear stress ratio variation, response spectrum, Fourier amplitude ratio versus frequency. The results indicate that accelerations were amplifed the most at the surface level. The range of peak ground acceleration (PGA) values obtained at the ground surface is about 0.2 g to 0.79 for a range of PGA considered at bedrock level (rigid half space at bottom of borelog) of 0.1 g to 0.34 g. The Fourier amplifcations of ground motion at surface are in the range of 4.14 – 8.99 for a frequency band of 1.75 Hz to 3.13 Hz. The maximum spectral acceleration at six locations varies in the range of 1.0 g – 4.71 g for all the seven earthquakes. The study clearly demonstrated the role for site effect and the type of ground motion on the ground response. For a given earthquake motion, amplifcation factors at surface level change by almost about 20% to 70% depending on local site conditions. Seismic Ground Response Analysis of Some Typical Sites of Guwahati City Shiv Shankar Kumar, Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India A. Murali Krishna, Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India Keywords: Amplifcation Factor, Deepsoil, Equivalent Linear Method, Ground Response Analysis, Spectral Acceleration INTRODUCTION An earthquake causes rupture along a fault plane and the generated seismic waves propagate through underlying bedrock and reach the earth’s surface. The amplification and de-amplification of ground motion from the bedrock to the surface depend on various stratification or geological parameters. For design of any earthquake resistant structure, selection of design ground motion play an important role. The design ground motion at bedrock level depends on various parameters like: faulting mechanism and its seismicity, local geology, surface topography, type of bed rock and dynamic properties of the soil medium DOI: 10.4018/jgee.2013010106