Deterministic Seismic hazard Assessment of Karora Hydro Power Plant

Abstract

Northern Pakistan is well known for its active fault system and seismicity. Thus to prior to any investment in
developing certain facility a through seismic analysis is unavoidable to justify the investment. The chosen location for
Karrora Hydro Power is District Shangla in the north of Pakistan, and thus a “Seismic Hazard Analysis” was inevitable
for this facility.
To evaluate the seismicity of the site data about characteristics of seismic faults was gathered from Provincial Disaster
Management Authority Punjab (PDMA). Source to site distance was calculated by delineating the geographical location
of the faults and Weir using QGIS. Similarly, for site characterization borehole data from seven boreholes, drilled at the
target site, was used. The average values of shear wave velocity are above 800 m/sec at all the locations.
Different attenuation relationships were adopted to calculate the Peak Ground Motion (PGA) at the target site, with the
equation of Akkar & Bommer (2013) providing more realistic results for the Active Shallow Crustal Region (ACR).
Among various PGA values corresponding to different active faults Main Mantal Thrust (MMT) has a maximum PGA of
0.35g. Akkar & Bommer (2013) is used to compute Response Spectrum for all the active faults and MMT. “Time History
Scaling” was performed, using wavelet method, for the target spectrum of MMT.