Seismic Hazard Analysis for Retrofitting of Mashhad Power Plant against the Earthquake

The Mashhad power plant is located in the eastern north of Iran in a region of high seismicity. A seismic hazard analysis was performed based on the most recent seismo-tectonic data to determine the design ground motion parameters. These parameters estimated four different design levels. The ground motion parameters for the Maximum Design Level (MDL), Design Basis Level (DBL) and Construction Level (CL) were obtained from a probabilistic seismic hazard analysis (PSHA) whereas the MCL was derived from a deterministic analysis (DSHA). The PSHA followed the conventional pattern consisting of the following elements: (i) identification of the seismic sources within a certain radius from the site, (ii) definition of the seismicity through a recurrence relationship for each source using the Kijko-Sellevoll approach, (iii) selection of suitable attenuation relationships, and (iv) generating curves showing the probability of exceeding different levels of ground motion at the site during a specified period of time. For the DSHA, the characteristics of faults within the area of interest was assessed based on topographic, geologic and aeromagnetic maps, air photos, field investigation, and a comprehensive search in the literature. Results are presented in terms of peak ground acceleration (PGA) and acceleration response spectra.