... overburden of up to 2525 meters. The question of the exact magnitude of the principal stresses at the tunnels depth has been an issue of considerable debate over time (Ge and Hou, 2012; Gong et al. (2010); Qian et al., 2009; Zhang et al., 2011), particularly since in situ testing did not provide conclusive...

... and applicability, it suffers from neglecting the influence of the intermediate principal stress. It is now generally recognized that while stress state at a point changes from triaxial compression (σ 1 > σ 2 = σ 3 ) to triaxial extension (σ 1 = σ 2 > σ 3 ), the peak strength of material increases...

..., especially in global stability analysis, is still limited. Upstream Oil & Gas 13th international congress Yang rock mechanics isrm13 impoundment Cheng principal stress hydrostatic pressure Reservoir Characterization pore pressure Biot coefficient reservoir geomechanics effective...

... three decades. Reservoir Characterization 13th international congress shale pipe simple numerical approach Upstream Oil & Gas time dependent log cycle Montreal principal stress confinement stress state suppression pressure reservoir geomechanics mechanism critical stress...

...). Because stresses within the salt are nearly isostatic, the principal stresses in the shales next to salt rotate, such that they become perpendicular and tangential to the contact with salt. 13th International Congress of Rock Mechanics ISRM13 10-13 May 2015, Montreal, Canada 5 MODELING OF SHALES IN SALT...

... (CCBO) technique, which is one of the stress relief method. The CCBO technique is the one of the suggested method of ISRM. Measurement period is from 1991 to 2014. Main results obtained in this study can be summarized as follows. The direction of the maximum principal stress did not change much before...

... principal stress rock mechanics isrm13 ROCK STRESS MEASUREMENT TECHNIQUE BY USING HIGH STIFFNESS HYDRAULIC FRACTURING SYSTEM *T. Yokoyama and K. Ogawa OYO Corporation 2-2-19 Daitakubo Minamiku Saitama, Japan (*Corresponding author: [email protected]) Innovations in Applied...

... Abstract Tests were carried out on clear glass blocks containing borehole aligned with and at an angle to applied principal stress states in order to study the growth of drilling induced tensile fractures. The samples were illuminated such that photoelastic fringes could be video recorded...

... preconditions for brittle failures can be defined by the ratio of the maximum tangential stress around an underground opening to the uniaxial compressive strength (UCS) (σ θmax /σ ci ) or by the ratio of the maximum far-field principal stress to the UCS (σ 1 /σ ci ). Both these indicators can be used to reflect...

... processes in NFRs. Reservoir Characterization hydraulic fracturing 13th international congress seismicity orientation energy release rock mechanics isrm13 Earthquake inclination Upstream Oil & Gas principal stress displacement seismic event pirayehgar radiated seismic energy...

... zone and the amount of energy dissipated in forming the crushed zone is the least. Upstream Oil & Gas rock fragmentation experiment diagonal pick orientation Efficiency specimen brittle damage principal stress reservoir geomechanics mostafavi free surface Reservoir...

... is in a compression state similar to a sample in a triaxial test. The maximum principal stress in the wedge A ( 1A) is equal to the stress transmitted by the foundation (q) if the weight of the rock is not considered. Wedge B is also under a stress state similar to the one presented in a triaxial test...

.... Especially in high tectonic stress filed, the state of original stress is invariably correlated with the prominent tectonic stress field. Normally, the directions of the maximum principal stress and the minimum principal stress are horizontal, while the middle principal stress is vertical and equivalent...

... borehole adhesive stress measurement reservoir geomechanics situ rock stress measurement measurement method experiment situ test principal stress Upstream Oil & Gas borehole DCCBO technique apparatus strain coefficient downward compact conical-ended borehole test site strain cell...

... and of limiting envelopes. Reservoir Characterization Mean stress envelope peak stress principal stress Upstream Oil & Gas Moca limestone MPa evolution Sorcy limestone carbonated rock strength compaction octahedral section limestone Soigny limestone reservoir geomechanics triaxial...

... the measure of the minimum principal stress ( s 3 ) and the level when the occurrences ceased represents the measure of the maximum principal stress ( s 1 ). Therefore, this test of cheap and simple performance is able to measure the magnitude of the minimum and maximum principal stresses, allowing...

... and certification pillar numerical analysis q-system value principal stress pillar 4 underground excavation Safety evaluation main stress Harmonising Rock Engineering and the Environment Qian & Zhou (eds) © 2012 Taylor & Francis Group, London, ISBN 978-0-415-80444-8 Safety evaluation of an underground...

... computer machine learning neural network information geometry excavation numerical model Rock stress rock mass fracture London principal stress rock engineering unsolved problem Harmonising Rock Engineering and the Environment Qian & Zhou (eds) © 2012 Taylor & Francis Group, London, ISBN...

... amygdaloidal basalt MPa Reservoir Characterization roof support pressure basalt thick plain shotcrete rail transportation Grimstad shotcrete situ stress parallel tunnel principal stress railway tunnel portal area support pressure plain shotcrete rock mass tunnel Harmonising Rock Engineering...

... ABSTRACT Samples of a fine-grained sandstone were tested under conventional (CTC) and true triaxial compression (TTC) conditions in an attempt to reveal the effect of confining pressure, intermediate principal stress and minimum principal stress on the mechanical behavior of rocks. Under CTC...