Probabilistic Seismic Hazards Analysis of Ambikapur-Chhattisgarh (India)

Abstract

The present study reveals the seismic hazard analysis of district headquarter Ambikapur, in the state of Chhattisgarh. Usually, seismic hazard study attempts to analyze two different kinds of anticipated ground motions, “the Deterministic Seismic Hazard Analysis (DSHA)” and “the Probabilistic Seismic Hazard Analysis (PSHA)”. The maximum Peak Ground Acceleration (PGA) has been estimated by using Iyengar and Raghu Kanth (2004) attenuation relationship. The regional recurrences relation is obtained by using available historical data and 33 numbers of seismic sources (liner faults) that are likely to cause ground motion, around the study area. The probabilistic seismic hazard analysis has been applied over Ambikapur, to assess the probability of exceedance for various PGA(g)values the seismic hazard curve has been developed by using Raghu Kanth and Iyengar (2007) attenuation relationship. Theprobability of exceedance for PGA(g) values as 0.01g,0.05g,0.10g,0.15g for their corresponding return periods have also been assessed. The liner seismic source having length 46kM, produced maximum peak ground motion as 0.15259g for recurrence period of 100 years. For Ambikapur district headquarter the probability of exceedance for 0.1g with a return period of 8788 years is estimated as 63.22%. Maximum Peak Ground Acceleration value and % probability of exceedance reflects that the seismicity of Ambikapur district headquarter is found to have exceeded from 0.1g as recommended by IS:1893 (Part 1): 2016 (Sixth Revision) for Chhattisgarh. Hence, it is recommended from present study that, Ambikapur should be included in zone III instead of zone II.