Stress Measurements
Overcoring up from 4.5-ft wide by 7-ft high gallery in a concrete dam with a Longyear CP-65 pneumatically driven core drill.
In-Situ Stress Determinations, Instrumentation, and Limited Access Core Drilling
Agapito Associates, Inc., (AAI) has the equipment and personnel for overcoring, sample coring, and instrumentation installation in limited access, surface, and underground mine locations.
Our drill rigs (Boyle Super 300, SD-1500, CP-65, and Ingetrol Explorer Jr 75E) are ideal for overcoring USBM Borehole Deformation or CSIRO Hollow Cell Inclusion gages, and our Strain Indicators and our Boyle Super 300 and CP-65 drill rigs are portable for difficult access locations and are permissible for use in “gassy” mines.
Our SD-1500 core drilling rig can be set up on tracks or skids and can be powered with a diesel engine, electric motor, or pneumatic-hydraulic powerpack. Our drill rigs are capable of drilling any angle from vertical down to vertical up.
Additionally, AAI provides services for measuring in-situ horizontal stresses using an innovative down-hole measurement instrument, developed by Sigra, Ltd. of Australia. The Sigra system is the most advanced biaxial overcore stress measurement system in the world.
Click here for more information: Sigra IST In-Situ Stress Measurement Tool
Sigra IST In-Situ Stress Measurement Tool
Security, safety, and environment are taken very seriously by everyone at AAI. Our “featured project list” provides examples of our ability to adhere to the specific policies, procedures, and protocols of our clients.
AAI has successfully measured in situ stress in copper, oil shale, molybdenum, trona, limestone and coal mines, and in tunnels and concrete dams since 1978. Since 1994, our current staff has completed 580 overcore stress determinations.
USBM BDG Method Overcoring Stress Determinations Since 1994
| Year | Client | No. of Successful Runs |
|---|---|---|
| 2010 | Resolution Copper | 4 |
| 2009 | HDR Engineering, Koewee Dam | 6 |
| 2008 | Oxbow Mining LLC, Elk Creek Mine | 5 |
| 2008 | UtahAmerican Energy Inc., West Ridge Mine | 4 |
| 2007 | Gannett Fleming, Roanoke Rapids Dam | 18 |
| 2007 | Canyon Fuels, SUFCO Mine | 2 |
| 2007 | Chemical Lime Company, Kimballton Mine | 11 |
| 2005 | Climax, Henderson Mine | 2 |
| 2004 | Andalex Resources, Aberdeen Mine | 4 |
| 2003 | Acres International, Robert Moses Niagara Power Project | 18 |
| 2003 | U.S. Bureau of Reclamation, Seminoe Dam | 19 |
| 2003 | FMC, Westvaco Mine | 12 |
| 2003 | OCI Wyoming, LP, Big Island Mine | 18 |
| 2002 | OCI Wyoming, LP, Big Island Mine | 6 |
| 2002 | Dravo Lime Co., Black River Mine | 15 |
| 2000 | Mountain Coal Company, West Elk Mine | 8 |
| 2000 | OCI Wyoming, LP, Big Island Mine | 40 |
| 2000 | NIOSH, Tanoma Mine | 2 |
| 2000 | CDC, Norton Energy Project | 6 |
| 1999 | CDC, Norton Energy Project | 2 |
| 1999 | Stone & Webster Engineering, Santeetlah Dam (Fall '99) | 15 |
| 1999 | Solvay Minerals | 35 |
| 1999 | Stone & Webster Engineering, Santeetlah Dam (Winter '99) | 15 |
| 1998 | Stone & Webster Engineering, Santeetlah Dam (Fall '98) | 67 |
| 1998 | OCI Wyoming, LP, Big Island Mine | 25 |
| 1998 | Energy West, Deer Creek Mine | 5 |
| 1998 | Bowie Resources, Bowie #2 Mine | 8 |
| 1998 | Stone & Webster Engineering, Santeetlah Dam (Spring '98) | 68 |
| 1997 | OCI Wyoming, LP, Big Island Mine | 14 |
| 1997 | Stone & Webster Engineering, Santeetlah Dam | 20 |
| 1997 | Energy West, Deer Creek Mine | 20 |
| 1996 | Solvay Minerals | 9 |
| 1995 | Solvay Minerals | 72 |
| 1994 | Sandia National Laboratories, DNA | 9 |
A CP-65 pneumatically powered core drill is mounted to the upstream face of a concrete dam for overcoring. A barge is tied off to the face of the dam for safe operation of the drill and overcoring activities.
Overcoring Horizontally in an Underground Trona Mine
