| Popis: |
An attempt has been made to carry out a detail seismic hazard analysis of the National Capital Territory of Delhi, India using earthquakes that are occurring at a radial distance of 500km from the center of Delhi including Himalayan sources. Tentatively, this area has been demarcated into five seismic source zones based on the recent past seismic activities and the geological faults. A comprehensive earthquake catalog is prepared and updated using different sources of catalogs like IMD. NCS, USGS, ISC, EMSC, JMA, etc. About 4000 earthquake data are considered in this study whose moment magnitudes are varying between 3.5 to 8.0 and the focal depth varies between 5-300km. The earthquake data showed that about 80% of the earthquake energy is realized from the shallow focal depth and the remaining earthquakes are occurring from beyond 100km focal depth. The seismic hazard parameters are estimated for these five seismic zones using Gutenberg- Richter relationship. GIS-based seven probabilistic seismic hazard maps (PGA) of NCT Delhi are generated using the output result obtained through the state-of-the-art probabilistic seismic hazard analysis(R-CRISS software) for the probability of exceedance at 50%, 20%, 10%, 5%, 2%, 1% and 0.5% at 50 years. For each probability of exceedance, the area of NCT Delhi is broadly demarcated into three levels of hazard zones based on the PGA values. Each zone has represented by a range of PGAs, a hazard curve and design spectra. These results may be useful for earthquake-resistant design and detailing structures, study of soil-structure interactions, soil liquefaction, and earthquake ground motion in the soft soil and soil response analysis in the NCT of Delhi. |
