Keynote Lectures:

Title:          Effect of Soil Stiffness on Seismic Response of Reinforced Concrete Buildings with Shear Walls
Authors:     Chinmayi H. K.
Abstract:   Buildings are subjected to lateral loads caused by wind, blasting and earthquakes and the high stresses developed literally tear the building components apart, which are in general designed for gravity loads. To resist these lateral forces, shear walls are introduced in buildings. Present study aims to determine the apt shear wall position which attracts the least earthquake forces in symmetric plan multi-storey buildings. Dynamic response of a structure is significantly influenced by the underlying soil due to its natural ability to deform. Three-dimensional finite element soil-structure interaction analyses of reinforced concrete shear wall buildings with shear walls placed at various locations is carried out in time domain using Elcentro ground motion and IS spectrum compatible earthquake motion, to determine the seismic response variation in the structure due to the effect of stiffness of soil. For this, linear elastic material behaviour for both structure and soil is considered. Four different soil types based on shear wave velocity and six varying shear wall positions in multi-storey buildings upto 16storeys are considered to determine the effect of soil-structure interaction. In addition, a comparative study on spectral acceleration and base shear obtained for the above cited structures situated at various site classes using provisions of international seismic codes IBC: 2012, EC8 and IS 1893:2002 is carried out based on simplified modal response spectrum analysis. Further, site specific ground response analysis and dynamic SSI analysis are carried out to determine the apt shear wall position in multi-storey buildings to be constructed at a local site based on the geotechnical investigation data. From the study, it is found that structural response as per conventional fixed base condition is very conservative. For buildings founded on soil with Vs ≤ 300 m/s, placing the shear wall at core is advantageous whereas for soil with Vs > 300 m/s the shear walls placed at exterior corners of the building attracts the least earthquake force.

Pages:        002-002

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