A2-2 Instrumentation Used in Support of the Geomechanical Monitoring System Parameter Instrument Type Features Measured Range Borehole The extensometer provides for monitoring the deformation parallel to the borehole axis. Units Cumulative 0-2 inches Extensometer suitable for up to 5 measurements anchors in addition to the reference head. Maximum Deformation borehole depths shall be 50 feet. Borehole Television Closed circuit television may be used for monitoring areas otherwise inaccessible, such as Image N/A Camera boreholes or shafts. Convergence Points Mechanically anchored eyebolts to which a portable tape extensometer is attached. Cumulative 2-50 feet and Tape Deformation Extensometers Convergence Meters Includes wire and meters. Mounted on rigid plates anchored to the rock surface. Cumulative 2-50 feet Deformation Inclinometers Both vertical and horizontal inclinometers are used. Traversing type of system in which a Cumulative 0-30 degrees probe is moved periodically through casing located in the borehole whose inclination is being Deformation measured. Rock Bolt Load Cells Spool type units suitable for use with rock bolts. Tensile stress is inferred from strain gauges Load 0-300 kips mounted on the surface of the spool. Earth Pressure Cells Installed between concrete keys and rock. Preferred type is a hydraulic pressure plate Lithostatic 0-1000 psi connected to a vibrating wire transmitter. Pressure Piezometer Pressure Located in shafts and of robust design and construction. Periodic checks on operability Fluid Pressure 0-500 psi Transducers required. Strain Gauges Installed within the concrete shaft key. Suitably sealed for the environment. Two types Cumulative 0-3000 µin/in and embedded. Deformation (embedded) 0-2500 µin/in (surface)
A2-2 Instrumentation Used in Support of the Geomechanical Monitoring System Instrument Type Features Parameter Measured Range Borehole Extensometer The extensometer provides for monitoring the deformation parallel to the borehole axis. Units suitable for up to 5 measurements anchors in addition to the reference head. Maximum borehole depths shall be 50 feet. Cumulative Deformation 0-2 inches Borehole Television Camera Closed circuit television may be used for monitoring areas otherwise inaccessible, such as boreholes or shafts. Image N/A Convergence Points and Tape Extensometers Mechanically anchored eyebolts to which a portable tape extensometer is attached. Cumulative Deformation 2-50 feet Convergence Meters Includes wire and meters. Mounted on rigid plates anchored to the rock surface. Cumulative Deformation 2-50 feet Inclinometers Both vertical and horizontal inclinometers are used. Traversing type of system in which a probe is moved periodically through casing located in the borehole whose inclination is being measured. Cumulative Deformation 0-30 degrees Rock Bolt Load Cells Spool type units suitable for use with rock bolts. Tensile stress is inferred from strain gauges mounted on the surface of the spool. Load 0-300 kips Earth Pressure Cells Installed between concrete keys and rock. Preferred type is a hydraulic pressure plate connected to a vibrating wire transmitter. Lithostatic Pressure 0-1000 psi Piezometer Pressure Transducers Located in shafts and of robust design and construction. Periodic checks on operability required. Fluid Pressure 0-500 psi Strain Gauges Installed within the concrete shaft key. Suitably sealed for the environment. Two types and embedded. Cumulative Deformation 0-3000 µin/in (embedded) 0-2500 µin/in (surface)
Attachment%20A2%2008-2016.docx