Rubble Belt

a rock belt, rock wall. It is set up with pieces of rock in the form of a belt in clearing operations in mining to support the roof from cave-ins; wood or metal bracings are used in conjunction with rubble belts. In setting up a rubble belt the waste rock from the driving operations and from specially driven rubble drifts is employed. Rubble belts allow the control of mine pressure, especially when there are unstable rocks in the roof of a bed. Sometimes pillars made of mineral ore take the place of the rubble belt. The width of a rubble belt is usually 6-12 m. Rubble belts are used in mining thin beds, veins, and lentils of minerals.