A5102905478- Geotechnical Engineering and Soil Mechanics
- Geotechnical Engineering and Soil Stabilization
- Geotechnical Engineering and Underground Structures
- Methane Hydrates and Related Phenomena
- Landslides and related hazards
- Grouting, Rheology, and Soil Mechanics
- Geotechnical and construction materials studies
- CO2 Sequestration and Geologic Interactions
- Climate change and permafrost
- Hydraulic Fracturing and Reservoir Analysis
- Hydrocarbon exploration and reservoir analysis
- Geotechnical Engineering and Analysis
- Soil and Unsaturated Flow
- Granular flow and fluidized beds
- Semiconductor Quantum Structures and Devices
- Rock Mechanics and Modeling
- Geotechnical and Geomechanical Engineering
- Spacecraft and Cryogenic Technologies
- Tree Root and Stability Studies
- Quantum and electron transport phenomena
- Advanced Semiconductor Detectors and Materials
- Arctic and Antarctic ice dynamics
- Landfill Environmental Impact Studies
- Soil Mechanics and Vehicle Dynamics
- Microbial Fuel Cells and Bioremediation
Yamaguchi University
2015-2024
Takeda (Japan)
2024
University of Yamanashi
2024
Tokiwa Park
1998-2020
Mitsubishi Heavy Industries (Japan)
2013
University of Auckland
2009-2010
Daewoo Electronics (South Korea)
2009
Korea Institute of Civil Engineering and Building Technology
2009
Fujitsu (Japan)
1998-2006
NTT (United States)
2005
This paper provides a micro-mechanical commentary on the macroscopic behaviour observed in DEM simulations of compression individual crushable grains, and triaxial tests assemblies both uncrushable grains. A fragmentation ratio is defined to describe bond breakage processes, significance other parameters such as sliding contacts ratio, average coordination number, deviator fabric, internal energies per unit volume discussed. Three different modes grain damage were observed: asperity...
Abstract A series of triaxial compression tests were conducted in order to investigate the mechanical behavior gas‐saturated methane hydrate‐bearing sediments, and a comparison was made between water‐saturated specimens. Measurements on specimens indicate that (1) larger hydrate saturation, failure strength more apparent shear dilation behavior; (2) stiffness increase with increasing effective confining stress pore pressure applied during compression, though specimen becomes less dilative...
Computer simulations of crushable agglomerates were performed using the PFC3D computer code, which adopts distinct element method (DEM). Agglomerates made by bonding elementary spheres in 'crystallo-graphic' arrays, and giving each sphere an existence probability 0·8. Weibull statistics crushing strength resulting agglomerates, when tested singly between parallel platens, matches that real silica sand grains. Triaxial tests on a cubical sample 389 then simulated. Curves isotropic compression...
Cheng and co-workers showed how to make numerical simulations of crushable soils by the discrete element method (DEM). Stress-path tests on triaxial elements comprising agglomerates have now been simulated. The plastic behaviour this numerically generated soil closely resembles that real sand. Crushing in aggregate begins at stresses less than one tenth characteristic strength single grains. yield surfaces isotropic ‘lightly overconsolidated’ DEM are also contours breakage, elliptical...
Abstract Methane hydrate‐bearing sediments with different amounts of fines content and at three densities were artificially prepared under controlled temperature pressure conditions. The void ratios specimens after isotropic consolidation tend to decrease a rise in content. particles enter into the pore space between sand grains densify specimens. A series triaxial compression tests performed systematically investigate influences density on shear properties hydrate‐free methane sediments....
Understanding the mechanical behaviors of carbon dioxide/methane hydrate-bearing sediments is essential for assessing feasibility CO2 displacement recovery methods to produce methane from hydrate reservoirs. In this study, a series drained triaxial compression tests were conducted on synthetic dioxide under various conditions. A comparative analysis was also made between and sediments. The stress-strain curves, shear strength, effects saturation, effective confining stress, temperature...
A series of undrained monotonic and cyclic triaxial tests were performed on silica sand at two initial densities different confining pressures from 0.1 to 5 MPa investigate their shear response crushing behaviour. The influence particle the strength pore-water pressure was examined. To clarify evolution crushing, terminated several distinctive stages sieving analysis subsequently tested specimens. In test, specimens exhibited remarkable dilation behaviour experienced no apparent low...
It is recognized that methane hydrate (hereafter referred to as MH) trapped in the sand sediments of alternating and mud layers turbidite Nankai Trough, Japan. The existence fines within marine sediment significantly affects its mechanical physical properties. A series plane strain compression tests at high pressures were performed order investigate effect particle characteristics content host sands on shear behaviour MH bearing sands. artificially produced using rounded glass beads three...
The round robin test (the simultaneous analysis of the same problem) is a method to investigate variance and sensitivity results provided by different analysts for given problem reliability particular software used each group participating in test. A has been conducted traditional numerical (e.g., finite difference method), but not yet discrete element (DEM). This paper presents first ever on DEM simulation angle repose, involving 16 groups from around world using softwares. Within scope...
This study evaluated bioelectricity generation by using kitchen garbage (KG) and bamboo waste (BW) as a solid management option microbial fuel cell (MFC) method. The nutrient content [nitrogen, phosphorus potassium (NPK)] of the by-products were also analyzed assessed for their potential use soil amendment. A one-chamber MFC was used in laboratory experiments both KG BW. data-logger recorded voltage every 20 mins at constant room temperature 25°C over 45 days. trend different two organic...
We studied the cluster size distribution of dislocation-free InAs/GaAs self-assembled quantum dots obtained by Stranski-Krastanow mode molecular beam epitaxy. The same scaling function was over a wide range dot density. indicated that fluctuation, normalized average size, is constant for all densities studied. resemblance to submonolayer homoepitaxial growth implies strain not essential factor determining dots.
Depressurization is an effective method to produce methane gas from hydrate reservoirs. However, during production, sediments consolidate due increasing stress. Revealing the compressive characteristics of hydrate-bearing sands consolidation essential for accurate understanding sediment properties and development a constitutive model. Therefore, series isotropic tests was performed on sand in which artificially generated, its compressibility were evaluated. Furthermore, assess prolonged...