Notes on flat jack test in rock mechanics

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August undefined, 2024

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.

Flat-jack method excavation Britannica

WebAug 25, 1976 · A non-dimensional set of results is given which enables one to use the jack with confidence, in rocks of various stiffnesses. N. Current techniques to measure the deformability of rocks in place are the plate bearing test (references 1,3,6,16,22), the borehole jack test (7,10,11,12,15), the flat jack test (1), and the dilatometer test (7,18,21). WebJul 5, 2024 · Flat jack tests are performed in slots at different orientations to allow in situ stresses to be estimated by recording the orientations of the slots and measurement-pin pairs, and the pressure required to deform the rock to its preslot position. Fig. 1 Four steps of flat jack test. ( a) Installing reference pins and measuring distances. small spoon with long handle

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WebAug 17, 2024 · The test is used to measure the acting stresses or mechanical parameters of structures. It's based on the stress release in a small area of a structure by cutting on a plane perpendicular to the … 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 … WebJan 1, 2024 · (2003) states that the ﬂat jack test is one of the earliest reported methods of in situ stress estimation. In addition, it is one of the simplest, direct and economical means of in situ stress... highway 7 road safety audit

Flat Jack Tests of Modulus And Stress of Claystone - OnePetro

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WebIt is concluded that there was very large variation in the results of in-situ stress by flat jack test as compared to hydraulic fracturing. The case study of another project in the same vicinity has been presented along with interpretation of data and a comparison with estimated stresses based on overburden. ... Rock Mechanics Aspects of Drill ... WebThe flat jack method is one of such techniques. Flat jack techniques are well established in the field of rock mechanics for determining stresses and material deformability in the … highway 7 service center newell iaWebThe test is performed by making a cut to a uniform depth into the mortar courses and inserting the flat jack or couple of jacks, which are pressurized to the desired level. Test … highway 7 saskatchewan accidents today

"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. " - Notes on flat jack test in rock mechanics

Notes on flat jack test in rock mechanics

Three dimensional consideration of flat jack tests - ScienceDirect

WebIn tunnels and underground excavations: Rock-mechanics investigation. …the drift, the so-called French flat-jack method is preferred. In this, a slot is cut at the surface, and its … WebIn-situ stress measurement test conducted in Khewra salt mine using Flat jack stress measurement technique.

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WebAug 18, 2024 · The flat jack is pressurized until the distance between the two points restores to the value before the slot was cut. These measurements are used to calculate the maximum vertical stress and minimum horizontal stress. Advertisement Synonyms far-field stress Share this Term Related Reading Tags Trenchless Construction Testing Methods 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.

WebJan 1, 2015 · Large flat jack test 1. Introduction In any analysis of rock mass mechanics, the deformation modulus is an important input parameter. The modulus of deformation describes the relationship between load (applied stress) and resulting deformations (strain) that include elastic and inelastic behaviour. 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 …

WebApr 1, 1986 · ISRM: DEFORMABILITY-LARGE FLAT JACK TECHNIQUE Suggested Method for Deformability Determination Using a Large Flat Jack Technique 133 SCOPE 1. (a) This test method is intended for the assessment of the in situ deformability modulus of rock masses using flat jacks in slots which are cut in the rock mass with a disc saw or by line drilling a … WebFinally, equilibrium is restored by inserting a device such as a jack in the slots. Then the jack is pressurized until all deformations have vanished. One of the most widely used jacking …

WebA flat jack test is used to measure the acting stresses or mechanical parameters of structures. The test is based on the stress release in a small area of a structure by cutting …

WebSep 25, 2024 · This lecture elaborates on In-situ stress, namely the flat jack test. It also details apparatus and procedures for site selection, preparation of individual ... highway 7 routeWebJan 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. small spoons with tapered endsWebNov 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 ... highway 7 speed limitWebOnePetro October, 2014. The deformability tests conducted by using plate jacking test, plate loading test, Goodman jack test and laboratory test show the comparison among different measurements and scale effects on deformability of rock mass. Plate load test, flat jack test and Goodman jack test give values of modulus of deformation which are 2 ... highway 7 peterborough to ottawaWebApr 1, 1986 · ISRM: DEFORMABILITY-LARGE FLAT JACK TECHNIQUE Suggested Method for Deformability Determination Using a Large Flat Jack Technique 133 SCOPE 1. (a) This … small spoons to fit in a thermosWebOct 23, 2010 · SYNOPSIS Large flat jack tests are used to assess rock mass deformability in the design stages of large projects. The paper introduces a methodology for interpretation … highway 7 service centerWebFeb 28, 2024 · Six flat jack tests (5-Horizontal & 1-Vertical) each were conducted on downstream (D/S) face as well as on upstream face (U/S) in random rubble stone masonry. Average Em values by flat jack... highway 7 storage