Site-specific probabilistic seismic hazard assessment for proposed smart city, Warangal

Abstract

In the present work, a probabilistic seismic hazard analysis has been performed for the newly formed Warangal Urban District, Telangana, India. The standard Cornell–McGuire method has been adopted considering different seismic zones. The area of influence chosen is having a radius of 500 km with NIT Warangal as the centre. An earthquake catalogue for the period 1800–2016 AD has been compiled and homogenized using global empirical relationships. Alternative models have been considered for seismic zoning scenario, completeness analysis of earthquake catalogue, maximum magnitude and ground-motion prediction equations (GMPEs) in the logic tree approach by assigning normalized weighs to each model, thereby reducing the epistemic uncertainty. Seismic hazard has been presented as the peak ground acceleration (PGA) and pseudo-spectral acceleration (PSA) maps at 5% damping for spectral periods T = 0.05, 0.1, 0.5 and 1 s at 2% and 10% probability of exceedance in 50 yrs period. The results obtained were compared with IS: 1893-1 (2016) (Criteria for earthquake resistance design of structures, Part-I. Bureau of Indian Standard, New Delhi, 2016) and NDMA (2011) (Development of probabilistic seismic hazard map of India, Technical Report of the Working Committee of Experts (WCE), National Disaster Management Authority (NDMA). Govt. of India, New Delhi, 2011) and they were found to be in excellent agreement. The profile of shear wave velocity (VS) was obtained by using the multichannel analysis of surface wave (MASW) method. The site was characterized as per NEHRP manual based on VS. The obtained shear wave velocity values are used in performing the 1-D ground response. A higher PGA has been observed at surface level when compared with the PGA values obtained at rock level suggesting seismic wave amplification due to subsoil condition.