Search results
Results from the WOW.Com Content Network
Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. [1] Shallow shafts , typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects.
Tunnels in the complex dug by Baldassare Forestiere The accidental discovery of one of Harrison Dyar's tunnels in 1924. Hobby tunneling is tunnel construction as a pastime. [1] [2] Usually, hobby tunnelers dig their tunnels by hand, using little equipment, and some can spend years or even decades to achieve any degree of completion. [2]
Sinking a dry shaft means that any water that flows into the excavation is pumped out to leave no significant standing or flowing water in the base of the shaft. When wet sinking a shaft the shaft is allowed to flood and the muck is excavated out of the base of the shaft underwater using a grab on the end of a crane or similar excavation method.
The sinking of its two shafts started in 1960. Its sandy and porous geology down to about 600 feet (180 m) was waterlogged. Boreholes drilled around each shaft position had sub-zero-temperature brine pumped through them to freeze the ground down to about 640 feet (200 m). The sinking personnel had to work in sub-zero temperatures until the ...
Tunnel Construction. Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management.
This was increased to a diameter of 16 feet (4.9 m) with a tunnel lining of 14 inches (350 mm). The overall diameter of the tunnel will be 20 feet (6 m). [22] This also increased the cost of the whole project (including sinking the mineshafts) from £3.6 billion to £4.2 billion. [47]
A tunnel ventilation shaft near Disley Golf Course in 2012. The construction method used was to drive the tunnel bore from both ends, while also sinking 11 shafts from the top of the hill along the path of the railway. Work began in 1900, and the miners worked both directions from each shaft, which allowed 24 simultaneous working faces.
On October 20, 1877, the shaft reached the hard rock layer of the transitional terrain, without having encountered the second layer of coal, which was considered a bad sign by the engineers. [4] In 1878, the sinking of the large shaft was completed. It reached a depth of 694 meters, while the small shaft reached 651 meters. [5]