Vs30 mapping at selected sites within the Greater Accra Metropolitan Area
| Autor: | Grace Nortey, Paulina Amponsah, Thomas Armah |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010504 meteorology & atmospheric sciences
Wave velocity Geology Soil science 010502 geochemistry & geophysics 01 natural sciences Metropolitan area Seismic wave Seismic hazard Shear (geology) Surface wave Earthquake hazard Soil water 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Journal of African Earth Sciences. 142:158-169 |
| ISSN: | 1464-343X |
| DOI: | 10.1016/j.jafrearsci.2018.02.020 |
| Popis: | A large part of Accra is underlain by a complex distribution of shallow soft soils. Within seismically active zones, these soils hold the most potential to significantly amplify seismic waves and cause severe damage, especially to structures sited on soils lacking sufficient stiffness. This paper presents preliminary site classification for the Greater Accra Metropolitan Area of Ghana (GAMA), using experimental data from two-dimensional (2-D) Multichannel Analysis of Surface Wave (MASW) technique. The dispersive characteristics of fundamental mode Rayleigh type surface waves were utilized for imaging the shallow subsurface layers (approx. up to 30 m depth) by estimating the 1D (depth) and 2D (depth and surface location) shear wave velocities at 5 selected sites. The average shear wave velocity for 30 m depth (Vs30), which is critical in evaluating the site response of the upper 30 m, was estimated and used for the preliminary site classification of the GAM area, as per NEHRP (National Earthquake Hazards Reduction Program). Based on the Vs30 values obtained in the study, two common site types C, and D corresponding to shallow (>6 m |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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