The Project is located at the south of Chesapeake Bay, and the new double submarine tunnel connects Portsmouth with Hampton.
2021 | 2023
The Project is located at the south of Chesapeake Bay, and the new double submarine tunnel connects Portsmouth with Hampton. The project involves the installation of approximately 111.000 m3 of jet grout treatment to provide ground stabilization of break-in, cut-cover invert plugs, organic layers and break-out at South Island and North Island before the excavation by TBM (2 parallel tunnels). All jet grouting treatments on the Project will be installed using a triple-fluid (air, water and grout), using a bottom-up installation procedure. Continuous monitoring of Jet Grouting parameters using PRS3 real time data collection system. Vertical measurement at each grout column. Column diameter Ø 3000 mm at approximately 30 m in depth, through variable soil formations including silt, sand and gravel/cobble layers. Contract provides the installation of extensive Test Programs prior the production work, with visual control of the treatments carried out and withdrawal of samples for laboratory analysis. Required unconfined compressive strength of cored samples of 2 MPa after 28 days curing for cored samples.
