DETERMINISTIC SEISMIC HAZARD ANALYSIS (DSHA) OF DHA PHASE-1, RAWALPINDI

Abstract

Rawalpindi and Islamabad are two of the most seismically active areas, located near the main boundary thrust (MBT).  Alongside this thrust zone are several faults: Murree, Margalla, Hazara, Jhelum, Rawat, and Riasi, which define the boundary between the Sub-Himalayan and Potwar Thrust (Monalisa et al., 2007; Khan & Khan, 2018). Due to the Destruction of high-rise buildings in Rawalpindi, the urgency for specific site seismic hazard assessment after the catastrophic earthquake of 2005 (Kashmir) was strongly felt in Islamabad & Rawalpindi. This study presents the deterministic seismic hazard analysis (DSHA) methodology for DHA Phase-1 Rawalpindi, located on the Potwar Plateau and an evolving commercial & residential region near the MBT system. This study summarizes the depth & foundation of DSHA by synthesizing and concluding existing seismic hazard studies for Islamabad and surrounding regions. The main four-step detailed process of DSHA is Determination of Source, Representation of source-to-site distance, and Selection of Ground-motion Estimation. In the literature, MBT Faults and Rawat Faults are located between 10 km and 30 km from the surroundings of DHA Phase-1 to control deterministic hazards, and these faults record Peak Ground Acceleration (PGA) estimated in the range of 0.15 g to 0.4 g based on controlling the fault. This analysis and results review form the methodological approach to give seismic microzonation and code compliance for DSHA for Site DHA Phase-1.