STRONG MOTION ATTENUATION RELATIONSHIP FOR SOUTH INDIAN REGION

Abstract

Accelerograms are the most detailed representation of earthquake ground motion and contain a wealth of information about the nature of the ground shaking. For the purpose of mitigating earthquake risk in terms of land-use planning and design of structures during ground shaking of devastating earthquake, estimation of reliable site specific characteristics is vital. South of 24N latitude is taken as South India in this study and based on the quality factor we have divided the South India into five sub-regions. Several devastating earthquakes have occurred in the past in South India but very few strong motion records are available for this 1-egion which can be further used for developing ground motion prediction equation. Several alternative procedures are available to compensate this scarcity of strong motion data. This report well presented the stochastic point source modelling technique for generation of synthetic strong ground motion. Based on the distribution of derived seismological model parameters, thousands of ground motion scenarios are generated for magnitude and distance range of engineering interest. The generated scenario are modeled through a simple quadratic function form of Ground Motion Predictive Equations (GMPEs) and regression coefficients are obtained for 12 discrete period values ranging from 0.1 to 4 sec and for PGA. The - standard error in GMPEs is also reported. The developed GMPEs are compared with regional GMPls and with next generation attenuation relations and are in good agreement.