Hydraulic model studies for backfilling mine cavities

Technical Report · Mon Oct 01 04:00:00 EDT 1973

OSTI ID:7301566

Carlson, E J

Hydraulic models of an idealized coal mine were tested to demonstrate the pattern of deposition of sand material by pumping a slurry of fine sand and water into the mine cavity. A distorted geometrical scale with the horizontal scale 1:24 (model to prototype) and vertical scale 1:8 was used first to give transport velocities in the model equal to transport velocities in the prototype. An undistorted model with a scale 1:24, was also tested in which transport velocities were not equal in the model and prototype. Prototype sand, 0.14 mm mean diameter, was used for backfill material in all model tests. Tests were made to simulate the following mine cavity conditions: (1) level floor with cavity submerged; (2) level floor with cavity dry; (3) sloping floor with bottom of injection hole submerged; (4) sloping floor with bottom of injection hole above the water surface; (5) corridor between pillars partially blocked and totally blocked; (6) solid walls on one and two adjacent sides of a retangular section of pillars surrounding the injection hole. Approximate bearing strengths of backfill material were determined by soils mechanics tests. Model tests showed that transport and deposit of backfill material depend on the flow of slurry in the mine cavity. Roof falls which block or partially block corridors affect the radial flow and deposit patterns of backfill material. (Author) (GRA)

• Research Organization: Bureau of Reclamation, Denver, CO (USA). Engineering and Research Center
• OSTI ID: 7301566
• Report Number(s): PB-225613/9; REC-ERC-73-19
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
BACKFILLING
COAL MINES
GROUND SUBSIDENCE
MINES