RESPONSE OF GROUND IN SEISMIC MOTION

Abstract

The response of ground during earthquakes governs the safety of the structure. The stress with which the base of the structure is subjected depends upon the source mechanism and the properties of the propagating medium, and other factors. In this dissertation analytical study has been attempted to evaluate the stress in sail near the ground surface, because of the propagated earthquake waves through the underlying rock medium. The implicit assumption is that the transmission of waves from the underlying rock formation can be considered as one dimensional upward propagation of shear waves towards the ground surface. The governing one dimensional wave propagation equation was transformed to frequency domain and then this was discretised for each layer for numerical computation. This study is mainly based on the elastic properties (linear or non-linear) of soil. The reliability of the results depends on the soil condition at the site. The presence of pore water, which might lead to 'Liquefaction of soil, may put its effect on the response of soil. in this dissertation, the empirical method of Seed and Idriss U970) has been modified by coupling it with the numerical scheme to find out the possibility of liquefaction. A detailed parametric study of the effect of layering, variation of shear modulus, etc. an the response of soil has been presented.