It is remarkable that three different tunnelbuilding methods are being used on this hydropower station construction site: excavator, drill and blast, and tunnel boring machine (TBM) advancement.
The Outstanding Underground Project
Honorable Mention
CSX Pinkerton Tunnel
As part of the National Gateway Clearance Project, the Pinkerton Tunnel, located in Markleton, PA, was to be removed because it did not have the required height clearance to accommodate double-stack freight railroad cars.
Where Are We Now with Sprayed Concrete Lining in Tunnels?
Traditional methods of sprayed concrete lining (SCL) tunnels (in soft ground) comprise a temporary primary lining of sprayed concrete with a sheet membrane inside and a permanent cast in-situ concrete lining, usually reinforced with steel bars
Reaching 20 MPa (2900 psi) in 2 Hours is Possible
In the mining and tunneling industries, time is critical; and as the mining/tunneling cycle becomes shorter, production increases.
Sustainable Shotcrete Using Blast-Furnace Slag
Two shotcrete mixtures were designed based on sustainability for use in mining ground support.
Ability to Access Restricted Space and Difficult-to-Reach Areas, Including Overhead and Underground
Accessing the site of a concrete pour can often be one of the biggest challenges faced by contractors.
Fort McHenry Tunnel Miscellaneous Structural Repairs
At the time of its construction, the widest underwater tunnel in the world, the Fort McHenry Tunnel in Baltimore, MD, was opened to traffic in 1985.
Rapid-Setting Cement in Shotcrete
Evolving technology in the shotcrete industry using a rapid-setting mixture with calcium sulfoaluminate (CSA) cement in lieu of a more common portland cement mixture is helping to meet the challenges for shotcrete repairs and underground projects throughout the world.