We have developed seismic velocity models for the heated rock surrounding a tunnel in Yucca Mountain tuff and compared the results with field data obtained at the Yucca Mountain drift scale test DST facility from 1998 to 2002. During that time, the tunnel was heated to replicate the effects of long-term storage of decaying nuclear waste and to study the effects of extreme temperatures on the su...

Shear failure is the dominant mode of earthquake-causing rock failure along faults. High fluid pressure can also potentially induce rock failure by opening cavities and cracks, but an active example of this process has not been directly observed in a fault zone. Using borehole array data collected along the low-stress Chelungpu fault zone, Taiwan, we observed several small seismic events (I-typ...

To study the coupled thermo-hydrologic-geomechanical processes and their influence on gas and nuclide transport in a two phase flow through the porous medium, a coupling of the thermo-hydrodynamic code TOUGH2 and the thermo-mechanic code FLAC3D is described and applied to analyze three dimensional gas, heat and nuclide transport in a repository for disposal of heat generating nuclear waste in a...

Coal fires have been found to be a serious problem worldwide in coal mining reserves. Coal fires burn valuable coal reserves and lead to severe environmental degradation of the region. Moreover, coal fires can result in massive surface displacements due to the reduction in volume of the burning coal and can cause thermal effects in the adjacent rock mass particularly cracks and fissures. The Wu...

BACKGROUND Hydraulic fracturing to extract natural gas from shale rock is a new, rapidly expanding industry in the United States (US). However, there is concern that these operations could be having large negative impacts such as groundwater contamination, increased air pollution and seismic events. The United Kingdom (UK) is looking at the potential for emulating the success of 'shale gas' in ...

Many natural examples of complex joint and vein networks in layered sedimentary rocks are hydro-fractures that form by a combination of pore fluid overpressure and tectonic stresses. In this paper, a two-dimensional hybrid hydro-mechanical formulation is proposed to model the dynamic development of natural hydrofractures. The numerical scheme combines a Discrete Element Model (DEM) framework th...

Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 fact...

A new model accounts for crystal growth patterns and internal textures in quartz cement in sandstone fractures, including massive sealing deposits, thin rinds or veneers that line open fracture surfaces, and bridge structures that span otherwise open fractures. High-resolution cathodoluminescence imaging of bridge structures and massive sealing deposits indicates that they form in association w...

Abstract Hydraulic fracturing is the most efficient method to exploit valued geothermal energy trapped in low-permeable hard rock, e.g. granite. Most research on hydraulic has focused its application shale gas and oil. However, performs differently reservoir, as rock properties are quite different. In this work, an anisotropic damage–permeability model developed fundament of continuum theory st...