ESTIMATION AND COMPARISON OF SEISMIC HAZARD ASSESSMENT USING DIFFERENT APPROACHES

Abstract

India is highly susceptible to frequent damaging earthquakes. A strong earthquake affecting a major urban center may result in damage and destruction of massive proportions and may have very severe long-term consequences for the entire country.. The earthquake risk at any location depends on the seismic hazard as well as the vulnerability of structures. Regarding to seismic hazard, there is an essential need of precise estimation of Peak Ground Acceleration (PGA) value for urban centers. Estimation and comparison of the seismic hazard in the Northern India using probabilistic approach and extreme value distribution approach have been studied in the present work. Seismic hazard assessment in Northern India has remained area of interest among the Seismologists, Geologists and Earthquake Engineers, due to presence of major urban centers, power projects and influence of Himalayan Belt. This region has experienced earthquakes at regular intervals that have caused immense damage in the past. At present stage, a lot of research work has been done regarding Probabilistic Seismic Hazard Assessment (PSHA) and also is going on through various agencies. In this present work, the objective is not only to assess seismic hazard but also to evaluate the best approach for seismic hazard assessment. The result of probabilistic seismic hazard assessment has been presented in the form of return period, probability of occurrence for various magnitude ranges and expected PGA by considering Design Basis Earthquake (DBE) and Maximum Credible Earthquake (MCE) at bedrock level. In the extreme value distribution approach, the results are presented in the form of return period and earthquake risk for various magnitude ranges. The results of seismic hazard assessment using probabilistic approach are more satisfactory than extreme value distribution approach. Hence it is preferable to use probabilistic approach for seismic hazard assessment of Northern India.