Mine

North Yorkshire holds one of the largest, high grade polyhalite reserves worldwide. It is located within the North York Moors National Park, ca. 1800m below surface. Once processed, this mineral functions as an organic fertilizer to boost harvest. Sirius Minerals plc are currently developing the infrastructure to mine the polyhalite. This operation requires deep shafts to access the mineral body but also demands an extensive mass transport system (MTS) to keep the impact on the National Park to a minimum. Therefore, at ca. 350m below surface, a series of SCL tunnels link the deep shafts to a conveyor belt system, which again connects the mining operation via a 37km TBM tunnel to its material handling facility.

Luck Stone Corporation (LSC) is the nation's largest family owned and operated producer of crushed stone, sand and gravel. At their plant in Leesburg, Virginia, Luck Stone Corporation acquired a new quarry, which is located to the West of Goose Creek river. An inter-quarry tunnel was constructed to link the existing South-Eastern pit with the new West pit. The tunnel's cross section is approximately 45 feet in diameter, and the tunnel's length is approximately 1275 feet. The tunnel crosses the Goose Creek river approximately 50 feet beneath. The excavation method was drill and blast in hard rock (diabase).

Luck Stone Corporation (LSC) planned to open a new quarry on the Western side of Goose Creek river, a component of the Virginia Scenic Rivers System. A tunnel was envisioned to connect the new Western quarry with the existing South-Eastern one below the river. The rock cover between the tunnel and the river was approximately 50 feet. The tunnel is 1275 feet long with a diameter of 45 feet. It is designed to accommodate large scale mining trucks as well as a conveyor belt for material transport which is scheduled to be installed in the future.

Inspected tunnel connects two quarries at the Luck Stone Corporation Fairfax plant. The tunnel crosses beneath the Lee Highway (US Route 29), in a North-South direction. Built ca. 1975, the tunnel is partially unlined and in rock; approx. 190 feet long and approx. 22 feet wide and 22 feet high. As the Northern quarry side is already exhausted, the tunnel is rarely used with just one or two transits per day.
Dr. Sauer & Partners performed an in-depth inspection of a connector tunnel; assessed the tunnel condition and provided remedial measures.