Details:

Creators:
Griffiths, Shawn C. ; Frazier, Josh D
Griffiths, Shawn C. ; Frazier, Josh D Less -
Corporate Creators:
University of Wyoming. Dept. of Civil and Architectural Engineering
Corporate Contributors:
Wyoming. Department of Transportation
Subject/TRT Terms:
[+]
Bridges Earthquake Resistant Design Seismic Design Seismicity Site Response Analyses Surface Wave Testing S Waves Training
Publication/ Report Number:
1905F
Resource Type:
Tech Report
Geographical Coverage:
United States ; Wyoming
United States ; Wyoming Less -
Edition:
Final Report; 7/1/17 – 7/30/19
Corporate Publisher:
Wyoming. Dept. of Transportation
Abstract:
Surface wave testing was performed as part of the sub-surface soil investigation for a bridge replacement project to be constructed within the next five years by the Wyoming Department of Transportation (WYDOT), over the Snake River near Jackson Wyoming. This investigation was performed in order to determine the shear wave velocity structure and seismic site classification for the site. The surface wave testing is part of a larger study to perform a site-specific seismic site response analysis for the site and determine if reductions in design ground motions can be justified. The site has sub-surface conditions consisting of gravels and cobbles (2.5 in. to 10 in. diameter material) that can present challenges for surface wave testing, and other investigation techniques. For both sides of the river active surface wave data was collected and analyzed using the Multi-channel analyses of surface wave (MASW) method. This data was combined with passive data collected using micro-tremor array measurement (MAM) techniques in both an L-array and nested equilateral triangular arrays. The triangular arrays included total side lengths between 20 and 200 meters. Horizontal to Vertical ratio data was also obtained, but was not used due to poor signal quality. The analyses of the collected surface wave data employed a joint inversion procedure using the layering ratio method. The inversion yielded site-specific shear wave velocity profiles. Both abutments classified as seismic soil Site Class D. In total over 448 analyses were performed in order to quantify the uncertainty in the analyses from the ground motions and shear wave velocity profiles. The site-specific analyses justified a decrease in the design spectral accelerations at most frequency/periods when compared with generic code based procedures. The site-specific seismic site response analysis provides more realistic seismic loading scenarios for the site under investigation. The reductions in spectral accelerations could result in significant cost savings for WYDOT.
Format:
PDF
Funding:
RS06217
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:1aee7d345d10b8760f2f12ae7ada93e7b443eb33f77bcc16a831cfde96e27483
Download URL:
https://rosap.ntl.bts.gov/view/dot/42491/dot_42491_DS1.pdf
File Type:

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