International Journal of Economic and Environment Geology (Jul 2022)

THE SEISMIC HAZARD AND SPECTRAL ACCELERATION FOR HYDRO POWER PROJECT IN GILGIT BALTISTAN PAKISTAN

  • SHAHZADA KHURRAM ,
  • Perveiz Khalid ,
  • Muhammad Irfan Ehsan ,
  • Shahbaz Muhammad

DOI
https://doi.org/10.46660/ijeeg.Vol13.Iss2.2022.680
Journal volume & issue
Vol. 13, no. 2
pp. 67 – 73

Abstract

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Peak ground acceleration is the maximum ground shaking intensity parameter in geophysics. To prevent the big loss of infrastructure, dam site or multistorey buildings as well as power project due to any seismic hazard, it is essential to mitigate the damages. Seismic hazard analysis for peak ground acceleration was carried out for hydropower project in Gilgit Baltistan to mitigate the effect of seismic natural hazard. Seismicity and tectonic map was drawn for distribution of seismic events. Study region was divided into seven source zones to rectify the vulnerability of region. Regression analysis and spatial distribution of focal depth charts were also prodcued to distribution the seismicity catalogue. Three distinct ground motion equations were used to predict the value of g with their return period as per site parameters. The actitvity rate analysis of seismic source zones were also drawn to determine the source contribution. Maximum credible earhquake, operational based earthquake and maximum design earthquake was detremined. According to the ICOLD and seismic risk reduction policy, the values of peak ground acceleration for Phandar hydro power project was 0.59g for maximum credible earthquake, for design basis earthquake g value was 0.311g for and 0.231g for operational basis earthquake with 475 years of return period at 50% probability of exceedence. Spectral acceleration for 0.1s, 0.2s, 0.5s, 1s and 2s was also computed for horizontal and vertical components. The values of spectral accleeration varied from 0.19g to 1.250g for maximum credible earthquake, 0.019g to 0.700g for design based earthquake and 0.050g to 0.480g for operational based earthquake. The results reveal that the maximum credible earthquake is to safety level, for serviceability level, operational based earthquakes and design based earthquake can be utilized

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