Bituminization of the rocks

BITUMINIZATION OF THE ROCKS (EN: bituminous grouting of rock; DE: Bituminierung von Gesteinen; FR: injection des produits bitumineux dans les roches; ES: relleno bituminoso de rocas; RU: битумизация горных пород) is the artificial filling of the voids and cracks within the massif of the rocks by the molten bitumen. It is purposed for the creation of the water insulation curtains during the construction of the mine workings and underground built structures for various purposes. The bituminization of the rocks has been used for the first time during the 1926 within the USA during the construction of the dam on the Tennessee river, and during the 1936 within the USSR during the construction of the foundations for the Palace of the Soviets of the USSR.

During the process of the bituminization of the rocks, they inject into the boreholes the bitumen, which has been melted within the cauldron for the boiling of the bitumen (the temperature of 200-220 degrees Celsius), under the pressure, which exceeds the hydrostatic one. For the prevention of the premature solidification, they heat the bitumen with the help of steam or electrical coil, which is installed within the pipe. While penetrating into the cracks, bitumen cools, solidifies, and prevents the penetration of the water into the mine working. The consumption of the bitumen (for example, during the construction of the "Moscow" swimming pool) is approximately 400 kilograms per 1 metre of the length of borehole with the distance between the boreholes of 0.75 metres. The disadvantage of the bituminization of the rocks is the plasticity of bitumen, which, under the hydrostatic pressure of the water of 0.2 megapascals, starts to flow and squeeze out from the cracks. Because of this fact, they use the bituminization of the rocks prevalently for the filling of the voids and cracks within the fixated space (for example, during the subway construction, the injection of the bitumen behind the tunnel lining for the purpose of the water insulation).