Method for counterstressing in situ rock for support of underground openings
Abstract
Abstract IN ROCK SURROUNDING AN UNDERGROUND EXCAVATION WHICH MUST HAVE A MAN-MADE SUPPORT SYSTEM TO ENSURE A REQUIRED DEGREE OF STRUCTURAL STABILITY AND WHICH IS SUBJECTED TO CERTAIN STRESS CONDITIONS, AN INFLATABLE DEVICE OR ROCK JACK IS INSERTED INTO A DRILL HOLE OR SLOT IN THE ROCK. THE ROCK JACK IS INFLATED SLIGHTLY BY FLUID PRESSURE TO TAKE UP ANY SPACE BETWEEN THE JACK AND THE IN SITU ROCK AND IS SUBSEQUENTLY PRESURIZED TO THE LIMIT OF ITS CAPABILITY. HIGH COMPRESSIVE FORCE IS TRANSMITTED TO THE ROCK, THUS CREATING COMPRESSIVE STRESS IN MONOLITHIC ROCK AND INCREASING CONFINEMENT OF AND FRICTION BETWEEN PROXIMAL BLOCKS OF ROCK WHICH ARE SEPARATED BY NARROW FRACTURES TENSION CRACKS, JOINT PLANES OR SIMILAR STRUCTURAL DEFECTS. SUCH ACTION MAINTAINS OR INCREASES THE NATURAL CAPABILITY OF THE ROCK TO SUPPORT ITSELF AND TO REMAIN STABLE BY UTILIZING THE INHERENT COMPRESSIVE STRENGTH OF THE ROCK.
Inventors
- 👤 Jerry M Whiting
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |