OverviewProjects :: Midtown Second Parallel Tunnel Beneath Elizabeth River Portsmouth & Norfolk, Virginia
Construction of a Second Parallel Tunnel beneath the Elizabeth River between the Cities of Norfolk and Portsmouth has been designated as one of the highest transportation-infrastructure priority for the Hampton Roads region of Virginia. Recognizing that the definition of river bottom and subsurface conditions are a key to the success of their proposed design-build-finance (3P) authorization of the project, the Innovative Project Delivery Division of the Virginia Department of Transportation (VDOT) hired Fugro Atlantic (Fugro) to characterize those conditions. VDOT will provide the results of Fugro’s marine survey and marine geotechnical exploration and site characterization to the 3P consortia offering to finance, design, construct, operate, and maintain the project in response to VDOT’s May 2008 Solicitation for Conceptual Proposals for the project.
The subsurface (base-line) reports that Fugro prepared interpret the subsurface data in context of the natural geologic conditions and historical uses of the sites. VDOT anticipates that this detailed understanding of the subsurface was far superior than the understanding obtained using only traditional, locally-available equipment and techniques and will directly reduce contingencies and uncertainties by 3P consortia responding to their design-build-finance solicitation.
Fugro’s scope of marine survey services included:
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Measurement of the river bottom bathymetry;
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Definition of the river bottom hazards and conditions; and
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Collection and interpretation of sub-bottom, and seismic reflection geophysical data.
Fugro’s marine exploration includes borings drilled using marine drilling techniques from one of Fugro’s Skate drilling barges and in situ cone penetration test (CPT) soundings, t-bar soundings, and vane shear measurements using Fugro’s Roson seabed testing system. All data are being compiled into and integrated within Fugro’s Geographical Information System (GIS) database to allow characterization of the river bottom and subsurface conditions at the Midtown Tunnel site.
The information developed by Fugro, and the integration of that information via a project GIS database has allowed Fugro to combine different types of data for the purpose of obtaining a fundamental understanding of the subsurface conditions and how man’s activities over the past 4 centuries have changed and affected those conditions. That knowledge will allow the future 3P consortia designers to design the project within the framework of understanding of the subsurface with much greater confidence that would be possible if only traditional investigation techniques and conventional reporting had been conducted.
Fugro’s fees for the integrated survey and subsurface exploration investigations and subsequent characterization evaluations are approximately $1.6 million.
Client Commendation:
I would like to thank Fugro for the quality of work product provided … Fugro has shown a willingness to coordinate with VDOT and make specific and favorable adjustments to the geotechnical exploration and subsurface characterization program, to the benefit of the project… I appreciate the significant effort Fugro has demonstrated in addressing VDOT’s needs, including fiscal stewardship (of VDOT’s funds). Getting all those borings done in 9 days is impressive, considering we threw the environmental samples on your team at the 11th hour. I’m impressed.
If you would like to learn more about this project and view examples of Fugro’s GIS illustrations, please follow the link below to the Virginia Department of Transportation Website. Please note that some of the files sizes are large. They may take several minutes to download, but are worth the wait!
