...-term increase in the horizontal stress, due to stress relaxation, was monitored. However, during the actual loading of the pile a large increase in horizontal stress on the shaft was observed, as a result of confined dilatancy. The results showed that this mechanism had a major influence on the pile...

... like material in which some of the parent rock fabric is retained. pile excavation decomposed granite excavation Reservoir Characterization load test result diameter test data skin friction construction drilling operation construction method horizontal stress Hong Kong interface...

... Reservoir Characterization Upstream Oil & Gas cavern service tunnel metals & mining displacement dimension reservoir geomechanics sylvinite Thickness pressure tunnel Artificial Intelligence overstressed zone underground excavation horizontal stress rock mass topography...

... hydraulic fracturing horizontal pressure extension fracture loading Upstream Oil & Gas adams horizontal stress cyclic process reservoir geomechanics fracture mechanics mechanism Gramberg Reservoir Characterization mining fracture s-shaped deformation stope regime stress...

...'-J j l ? FRACTUIfATED ZONE j l , ilFig-11 from D. GRAULS (SNEA.P) 1Jll1YJ@IFBIl ~. ® (s.g·EMW) I P ;, CT3 P = FLUID PRESSURE a 3 = HORIZONTAL STRESS CT1 =VERTICAL STRESS FG = FRACTURATION GRADIENT 1544 Within the upper part of the normally compacted section, a large dispersion of the LOT values can...

... in situ stress, the vertical stress in this case. The data in Table 1 suggest a difference of 0.4 MPa between the vertical and the minimum horizontal stresses at well 1. The instantaneous shut-in pressures derived from plots of the time derivative of pressure for each cycle are marked on the pressure...

... discing. Paillet and Kim (1987) describe 'saddle shaped' or 'potato crisp' shaped discs in basalt, interpretated as an indicator of anisotropic horizontal stresses. The axis of the peaks yield the direction of the minimum horizontal stress (Lehnhoff et al., 1982). Maury et al. (1988) in a review...

... surface are located at the azimuth of the minimum horizontal stress. One type of failure is characterized by straight or diffuse breakout margins. In crystalline rock, these breakouts are first detected as small pits in the well bore surface. In sedimentary rock fracture zones at breakout margins...

... are too high given the reduction in revenues (reported by Woodlands [1988] at $60 million for Western Canada alone). Second, breakout geometries are being utilized as indicators of magnitude and orientation of the in situ horizontal Stress field (Gough and Bell, 1982; Zoback et aI., 1985; and Haimson...

... of symmetry and lateral restraint yxy'' Yxz'' Yyz'' EX and Ey vanish. If the rock mass is transversely isotropic in planes perpendicular to the ground surface. unequal horizontal stresses will be induced in the x and y directions. From this brief discussion of stresses due to gravitational loading...

... within mining depths of deposits (2-) km)are in post-failure stress-strain state. It explains the fact, that horizontal stresses in seismically active folded areas at equal depths below surface have 1,5–2,0 times smaller values than in the rock masses of the ancient stable consolidated shields (Baltic...

... tensor tube Reservoir Characterization rock stress determination stress determination rock mass interpretation reservoir geomechanics vertical stress initial state horizontal stress stress measurement STT Alto Lindoso strata tunnel Proceedings of the Intemational Symposium on Rock Stress...

... stress component derived from overburden load. This is especially important if such a measurement is to be considered representative of a large area. reservoir geomechanics stress component vertical stress component Reservoir Characterization average horizontal stress horizontal stress...

... shaft station reservoir geomechanics atomic energy Reservoir Characterization Upstream Oil & Gas information horizontal stress situ stress proceedings Canadian Shield underground research laboratory Canada shaft fracture instrument ring metals & mining solid waste management...

... records obtained from a hydraufracturing operation could be used to determine the in situ stresses. hydraulic fracturing Proc horizontal stress determination Reservoir Characterization orientation borehole assumption reservoir geomechanics shut-in pressure principal stress Haimson...

... but it is only inclined to the vertical less than 30 degrees. So it is still reasonable to recognize that one of the three principal stresses is vertical and the rest are horizontal. The vertical principal stress is related to the overburden weight and the horizontal stresses represent the regional tectonic...

... those in rock masses free from tectonic stresses.. The characteristic feature of the tectonically stressed rock masses is the horizontal stresses (бh) exceeding the vertical ones (бv). This being true, in the general case the vertical stress (бv) agrees with the calculations v from the bulk weight (γ...

... and its variation with depth has been determined reliably. The maximum principal stresses are subject to some uncertainty but the results do show that there is a severe and persistent anisotropy between the horizontal stresses. The orientation of the stress field is in good agreement with results from...

... ABSTRACT: Several underground hydroelectric plants in the Niagara Falls region are showing signs of structural distress as a result of preexisting high horizontal stresses and time-dependent rock deformation upon stress relief. Thus, a major emphasis in the feasibility and preliminary design...

... the hydraulic system. All field work is conducted by two persons. Reservoir Characterization Stephansson breakdown method luleå university reservoir geomechanics gidea horizontal stress packer pressure Upstream Oil & Gas borehole breakdown pressure Haimson tensile strength Rock Stress...