...-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...

... tends to reach the vertical stress value σ1. reservoir geomechanics sonic transit time Reservoir Characterization Upstream Oil & Gas sedimentology sedimentation horizontal stress compaction undercompacted zone structural geology transit time Significance evolution shale sonic...

... Horizontal Vertical Minimum (m) (MPa) (MPa) 1 487 10.2 9.8 2 488 10.2 9.8 3 490 10.3 9.9 4 490 9.9 nature of the pressure responses, the minimum in situ horizontal stress at each well's perforated interval were inferred as indicated in Table 2. Table 1 shows that for well 2, no re- orientation of the stress...

...' 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 reviev of discing, highlight the repetitivness in shape of discs. They conclude that even...

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

... as indicators of magnitude and orientation of the in situ horizontal Stress field (Gough and Bell, 1982; Zoback et aI., 1985; and Haimson and Herrick, 1986 amongst others). Whereas many factors contribute to the formation of breakouts, the problem is primarily stress related. Stress redistribution due...

... Reservoir Characterization Thickness plane expression coordinate system reservoir geomechanics variation gravitational loading rock mass stiffness Upstream Oil & Gas pgz jointed rock mass rock unit transversely isotropic horizontal stress stratified rock mass Amadei...

... Reservoir Characterization inhomogeneity Upstream Oil & Gas higher stress virgin stress state equal depth crust horizontal stress strength variation upper part rock mass stress measurement reservoir geomechanics different part tectonic force stress state stress-strain state...

... 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...

... Reservoir Characterization tectonic stress field horizontal stress shear stress Engineering upper crust application reservoir geomechanics variation stress state stress measurement Upstream Oil & Gas situ stress measurement stability China maximum horizontal stress field...

... 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...