1. Nonlinear Seismic Site Response Analysis of Shallow Sites in Dhanbad City, Jharkhand, India.
- Author
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Shams, Rashid and Agrawal, Mohit
- Subjects
SEISMIC response ,GROUND motion ,WAVE amplification ,SHEAR strain ,SEISMOGRAMS ,NEPAL Earthquake, 2015 ,SEISMIC waves - Abstract
The understanding of the amplification of seismic waves due to local soil deposits is critical to assessing the ground-level seismic hazards in any region. In the present study, 1D non-linear seismic ground response analysis is carried out for various sites in Dhanbad City of the Indian state of Jharkhand. We have used Standard Penetration Test (SPT) data from eleven sparsely located boreholes spread all over the city. Two earthquake records viz. Nepal (Gorkha) 2015 and the Imperial Valley (1979) earthquakes are adopted as bedrock input motion for the study. The final ground-level responses were estimated for acceleration, strain, shear stress ratio, and Fourier amplitude ratio. The results reveal that various sites in Dhanbad exhibit high to moderate amplification of the bedrock ground motion with a ground acceleration amplification ratio ranging from 1.3 to 3.5. Some sites such as BH-9 (FDC, IIT (ISM)) and BH-10 (Press Club) displayed very high amplification with an amplification ratio ranging beyond 3. The observed amplification variations are correlated with the type and dynamic nature of local soil deposits. The shear strain ratio values varying from 0.25 to 0.6 and 0.14 to 0.28 for Imperial Valley (1979) and Nepal (2015) motions imply the presence of soft and unconsolidated deposits near to the ground surface. The response spectrum obtained from the analysis can be used by structural engineers in designing earthquake-resilient infrastructure. The ground-level accelerations obtained from this study can further aid in the development of detailed microzonation maps for the district. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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