... three sampling intervals, the 1.0 mm interval is pointed out the most appropriate one to evaluate the joint roughness. In addition, we evaluated and compared the JRC values of joints within granite specimens that have different mechanical properties and weathering state by two different methods (Z 2...

... and physical properties, accounting for the grain scale heterogeneity observed in natural granular rocks. The simulations showed that rock specimens characterized by a wide grain size distribution are weaker than those with a narrow grain size distribution, but that spherical grains do not significantly...

... shear tests were conducted under the dried and immersed conditions to measure a residual strength (τ res ) of the specimen. In a direct creep shear test, the specimen was subjected to immersion under creep shear stress conditions (σ v = 25, 100 or 200 kPa, τ = Rσ v , R = 0.7~1.0). After the creep shear...

... surface to investigate the shear characteristics of a rock discontinuity under various thermal -hydro-mechanical (T-H-M) conditions in a triaxial compression chamber. In addition to the tests on saw-cut specimens, the effect of surface roughness on shear characteristics was examined. Cement-mortar...

... provide a preferential pathway for radionuclides to migrate. Laboratory scale biaxial compression tests were performed using 170 mm cubic cement mortar specimens with a circular opening in the center to simulate and investigate the brittle failure process around the underground excavations. Acoustic...

... and dynamic fracture toughness tests were performed with straight notched disc bending (SNDB) specimens of Yougnju granite to investigate the microcrack induced fracture toughness anisotropy. In order to conduct dynamic fracture toughness test, split Hopkinson pressure bar (SHPB) apparatus using pulse shaping...

... complex reservoir Olmo hueckel pellegrini Canada Reservoir Characterization structural geology mechanism clay fraction anisotropic thermal strain behavior thermal strain behavior specimen different clay fraction thermal plastic strain Upstream Oil & Gas shale soft mudrock Zhang...

... pumping rate to fracture the granite specimen under certain stress conditions. When the pumping rate is lower than the threshold value, water infiltrates granite matrix with slow increment of injection pressure, and the specimen finally reaches a completely saturation state without fracturing. Injection...

... Abstract This study prepares rock-like intact specimens and specimens that contain singly, smoothly planar joint with various joint angles for the SHBP test. A buffer pad between striker bar and incident bar of a SHPB apparatus is utilized to absorb part of shock energy, and thus generates...

... Abstract In order to investigate the influence of several factors on the mode-I fracture toughness and fracture behavior of rocks, fracture toughness tests were conducted under various conditions of specimen shape and size, loading rate, confining pressure and water vapor pressure...

... using ultra-high speed photography, and the deformation fields of the plate specimen during dynamic loading process were obtained using DIC method. The crack propagation velocity and fracture toughness were obtained combined the deformation field with fracture mechanics analysis. Results show...

..., mode I, mode II, mode III fracture toughness tests were performed with the same loading rate of strength tests. Grooved disc specimens, short beam compression specimen, and circumferentially notched cylindrical specimens were employed for fracture toughness tests. The results show that both rock...

... now. Therefore, the X-ray CT method was used for visualizing change in internal structure during expansion fracture. The mechanism of the phenomenon was then clarified. Concrete cylinders with a diameter of 50mm and length of 100mm were prepared as specimens. In the laboratory, the expansion occurred...

...-ray computed tomographic images. The method is validated by using a wide range of synthetic images and is applied to 6 rock specimens collected in Korea. Results highlight that the proposed method enables quantitatively defining the representative size in rocks. 1. Introduction Naturally existing...

... well drilling, and hard rock breaking. Therefore, a method of impact-shear is proposed on shale breaking. reservoir geomechanics Wellbore Design strength drilling fluids and materials relation shale gas Upstream Oil & Gas Rock mechanics specimen Science Foundation geomechanics...

... of characteristics of lack-of- earthquake analysis method, In this paper, based on a uniaxial compression process acoustic emission testing of phyllite, quoted the lack-of-earthquake analysis method, and analyzed the lack-of-earthquake phenomena before the peak stress in view of phyllite specimens with different...

... Brazilian Disc specimen (CSTBD) by MTS Landmark testing machine. In the work, two splitting Brazilian loading methods according ISRM standard (method I) and China standard (method II) were employed. The difference between the fracture mechanical behavior of method I and II were very apparent. For fracture...

... necessary. strength mechanism threshold migmatitic granite Reservoir Characterization cyclic loading Loading Rate MPa granite Upstream Oil & Gas test specimen specimen loading metals & mining ae characteristic acoustic emission single loading peak strength strength threshold...

...-pit slope to study the spa- tial distribution of the tertiary soft rock layers. The specimens were sampled from the rock cores of the geological exploration drilling holes distrib- uted in different parts of the stope. In order to keep the original moisture content, all the specimens were wrapped up...

... consolidation curve high pressure consolidation elastic-plastic mechanical feature Upstream Oil & Gas consolidation experiment mechanical property preparation requirement Gaomiaozi bentonite compaction density Fluid Dynamics consolidation test specimen constitutive model deformation...