In situ observation and evaluation of zonal disintegration
Aug 14, 2018 · The formation mechanism of zonal disintegration induced by the existing fractures is numerically investigated. Only new fractures, extension and propagation of fractures, and failure, induced by the excavation, are observed at these zones. No excavation-induced fractures occur at other positions in the boreholes, and the rupture range
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Shear Origin of Tension in Excavation-Induced Fractures
The authors hypothesize that excavation-induced extension fractures are caused by elastic shearing displacement that in turn causes tension oblique to a propagating shear zo ne. Such extension is manifested as tension on scales larger than that of microcracks. En …
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APPLICATION OF EQUIVALENT MATERIALS TO MODELING …
The formation of a mining-induced fracture and the mechanism of accidents caused by the mining-induced fracture are analyzed. The results show that the footwall strata underwent a more notable movement compared to the hanging wall strata. Hence, the mining-induced fracture height of the footwall is higher than that of the hanging wall.
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Mechanics of Electric Rope Shovel Performance and
May 12, 2016 · Large-capacity rope shovels are used as primary production equipment in many surface mining operations. Current rope shovels have payload capacities in excess of 100 tons per pass. The dynamic payload and formation resistive forces result in severe stress loading of the shovel front-end assembly. Material flaws, high stresses, and harsh excavation conditions can initiate cracks in the …
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a) Stress distribution b) Areas of potential tensile failure
Figure 6.12 Effect of induced fracture coalescence. The narrow zone between those fractures, which completely split individual layers, is allowed to "crush" Figure 6.12 shows how the presence of fractures can lead to the effective widening of an excavation as the hanging- and footwall regions become de-stressed. De-stressing has been
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Brittle Rock Fracturing Mechanisms in Deep Gold Mines
The presence of parting planes in the model explains the absence of the stope-parallel extension fractures in the field observations as well as how shear fractures are formed ahead of the stope face. In the coupled FLAC - PFC 2D models, the bonded-particle material exhibits formation of conjugate shear fractures that correspond with shear
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Kantia, Pekka; Kiuru, Risto; Rinne, Mikael Effects of
cracking, (3) zone of extension and expansion of fractures and (4) elastic zone where no cracks are formed (Figure 1). Siren et al. (2014) separate the most important formation mechanisms of EDZ as (1) EDZCI - Construction induced excavation damage zone, which is instantly formed by the construction
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(PDF) Shear Origin of Tension in Excavation-Induced …
The authors hypothesize that excavation-induced extension fractures are caused by elastic shearing displacement that in turn causes tension oblique to a propagating shear zone.
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Formation mechanism of extension fractures induced by
Jan 01, 2013 · The extension fractures have associated with plumose structures on the plane (Fig. 6e). The extension fractures terminate against shear fractures, and the fracture nucleation points are recognized on the floor of the excavation (Fig. 6f). The extension fractures are classified into two sets (Fig. 7d). The first set is characterized as NW-SE to N-S striking fractures, dipping moderately …
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Formation Mechanism and the Height of the Water-Conducting
Apr 01, 2021 · The height of the water-conducting fractured zone (WCFZ) is a basic parameter related to water protection in coal mines and is also crucial for aquifer protection and mine safety. In order to accurately detect the height and shape and reveal the formation mechanism of the WCFZ, which is caused by middle-deep coal seam mining in a sandy region, the 112201 coalface at the 1# coal …
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EDZ and Fracturation
The deformation mechanism responsible for simultaneous formation of the extension fractures in the tunnel walls. Bedding-parallel slip in reactivated bedding planes, as is the case for the tunnel floor and ceiling, may continue over To separate the borehole-induced fractures from …
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Applied Sciences | Free Full-Text | Experimental Study on
Nov 25, 2021 · In situ stress is one of the most important factors affecting rock dynamic fractures during blasting excavation of deep rock mass that generally is hard rock. In this research, crater blasting experiments on hard rock under different uniaxial static stresses were conducted to investigate the initiation and propagation process of crack networks that were induced by coupled dynamic and static …
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Formation mechanism of extension fractures induced …
Formation mechanism of extension fractures induced by excavation of a gallery in soft sedimentary rock, Horonobe area, Northern Japan Tetsuya Tokiwa a,*, Kimikazu Tsusaka a, Makoto Matsubara b
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FRACTURE CONTROL IN THE HANGINGWALL AND THE …
formation of primary and secondary fractures ahead of an advancing stope face, (After Brummer and Rorke, 1984), Daformational mechanisms around a stope. (After Brummer, 1986a), Tensile zones above and below an isolated tabular excavation at great depth. (After Salamon, 1974), Elastic predictions of …
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3: Hypothetical results from 62 pull-out tests on 17 mm
Formation mechanism of extension fractures induced by excavation of a gallery in soft sedimentary rock, Horonobe area, Northern Japan Article Full-text available
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(PDF) Formation mechanism of extension fractures …
Formation mechanism of extension fractures induced by excavation of a gallery in soft sedimentary rock, Horonobe area, Northern Japan January 2013 Geoscience Frontiers 4(1):105–111
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Brine release based on structural calculations damage
stress, brittle intergranular fracture, and (3) low con- fining pressure, cleavage fracture. Again, dislo- cation mechanism-induced strains and the fracture mechanism-induced strains are additive. Coupling between the creep and fracture processes occurs because the formation of damage (microfrac-
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Microseismic Monitoring of Rock Mass Fracture Response to
Nov 26, 2021 · The formation of the V-shaped notch has a stress insensitive period. underground excavation induced rock mass degradation or damage can be located. The fracture mechanism of moment tensor
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Fracture Characterization and Rock Mass Damage …
Up to12%cash back · Jan 03, 2017 · The tendency corresponds to that Tokiwa et al. studied with a gallery in the Koetoi Formation, and the stress release induced by excavation occurs by the formation of the extension fractures in the intact parts of the soft sedimentary rocks in both the shaft and gallery. In addition, pre-existing fractures present planes of relative weakness in the rock mass and, therefore, it …
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Experimental and Numerical Investigation on Hydraulic
mechanism of hydraulic fracture propagation at the bedding ing a constant static pressure in the hydraulic fracture ignore the induced stress in the direction of perpendicular to the fracture [24]. The Mohr-Coulomb failure criterion is used the hydraulic fracture extension mode comprehensively.
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