WebSep 21, 1981 · The flat jack test offered an approach in which, by testing rock deformability parallel to the rock surface, the tendency to rock disturbance may be less than for loading tests perpendicular to the surface, because of restraint by in situ stress. WebJan 1, 2024 · The flat jack test is one of the oldest and simplest in situ stress measurement techniques that has generally fallen out of favour in current rock engineering practice.

International Journal of Rock Mechanics & Mining …

WebDec 21, 2016 · Determination of rock stress- Code of practice, Part 3: Using a CSIR or CSIRO type cell with 9 or 12 strain gauges: IS 13946-4 (pdf) IS 13946-4 (txt) 1994: Determination of rock stress-Code of practice, Part 4: Using flat jack technique: IS … WebNov 20, 2012 · After 4 months, the flat jack test results are within the stress range determined with the strain gauges. On the contrary, after 2 years the stress values estimated on the basis of strain gauge measurements are considered to be an upper bound to the state of stress in the concrete lining and the stress relief tests may be reasonably considered ... dw \\u0026 bi solution road-map

Flat-jack method excavation Britannica

WebThe Flat Jack method is a “cancellation” in-situ stress test method, in which a thin slot is cut into the rock surrounding an underground opening and a pressure gage is inserted into … WebDec 10, 2016 · This test is intended to measure in situ deformability of rock mass by inserting flat jacks into slots cut into rock using a rock saw or a series of overlapping drilled holes (Loureiro-Pinto 1986) (Figs. 2 and 3 ). The test can be performed on up to four coplanar slots simultaneously. WebSpecimens are placed in a triaxial cell and subjected to the predetermined stress condition in terms of confining pressure (related to uniform horizontal stress), vertical stress (over-burden stress) and pore pressure. Injecting a constant flow rate into the cavity hole pressurizes the specimen. dwtx torrent