“Development of PGA maps and spectrum compatible acceleration time histories for Chennai using hazard and ground response analyses”
Date18th Jan 2021
Time03:00 PM
Venue Google Meet
PAST EVENT
Details
Infrastructure facilities and new structures proposed in an area have to designed for the expected level of ground shaking without experiencing excessive damages. The seismic design parameters provided in the building codes express the intensity of ground shaking to be experienced by the particular site in an area during an earthquake and are mapped for the conventional ground conditionson a national scale. In the case of infrastructure facilities and important structures, the code-based seismic design loadings are inappropriate.In the present study, an attempt is planned to develop spectrum compatible acceleration time histories for different return periods for the study area involving the entire greater Chennai corporation. Recently, Chennai corporation has given more impetus for the developmental activities in the form of infrastructure facilities and commercial establishments. This has led to the need for comprehensive seismic hazard studies in the greater Chennai corporation area. Ground response studies are also needed along with the hazard studies to obtain the peak ground acceleration (PGA)maps and spectrum compatible acceleration time histories at different depths for the entire study area. The results of hazard and ground response analyses can be used to develop easy to use 2D and 3D PGA maps for the Chennai city along with spectrum compatible acceleration time histories. The conventional probabilistic seismic hazard analysis (PSHA) considers only the aleatory uncertainty. In this study, it is proposed to consider the epistemic uncertainty in the hazard analysis using fuzzy-probabilistic hazard analysis (FPSHA). In the analysis, the appropriate and recently developed ground motion prediction equations (GMPEs)will be used for developing fuzzy attenuation relationships incorporating fuzzy inference rules in the framework ofadaptive neuro-fuzzy inference system (ANFIS). A preliminary study is attempted and seismic hazard curves and uniform hazard spectra for different return periods are obtained for the Chennai city. It is also proposed to develop comprehensive 2D and 3D microzonation maps for the greater Chennai corporation area. These maps along with ground motion data are very useful for engineers to design new structures and facilities for earthquake resistance and seismic safety assessment of existing and heritage structures.
Speakers
Ms. Menaka, K, Roll No. CE16D024
Department of Civil Engineering