Drilling of large-diameter boreholes is regarded as an effective measure for rockburst prevention. By investigating the morphological characteristic and evolution plastic zone in borehole surrounding rock, pressure-relief mechanism was ascertained, engineering application assessed 13230 working face Gengcun Coal Mine, Henan Province, China. The results showed that (1) rock appear circular, elli...

To solve the safety hazard of a buried gas pipeline caused by subsidence mined-out area, three-dimensional model in area was established using geological parameters and finite-element software ABAQUS. The effects friction coefficient pipe soil, coal-seam dip angle, horizontal angle on mechanical behavior under varying widths goaf were investigated. results indicate that maximum equivalent stres...

There are lots of cleats, fractures and many other structure weak planes in coal seams, which make the bullet holes and cleats intersecting. During the hydraulic fracturing process in coal seams, fractures will initiate at coal rock body of borehole wall, and cleats or fractures are different from conventional reservoirs. Thus a new model for initiation pressure calculation during coal seams fr...

Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribut...

With the shift of coal resources to deep mining, occurrence long-distance seams has increased, and protective layer mining is facing new challenges. This paper attempts explain stress evolution law upper group in lower Pingdingshan No. 8 Coal Mine. A simulation model advance lower-group was established. The seam under influence advanced disturbance studied. following conclusions were obtained: ...

This study systematically investigates the overburden movement and strata behavior at a fully-mechanized top coal caving (FMTCC) face in a thick coal seam in a loess-covered gullied region by field measurement and theoretical analysis. A comparative analysis was performed to examine how the attitude of surface gullies and the structure of overburden affect face support resistance. The character...

It is with some concern that we note in Boreham et al. (1998) detailed reference to our earlier work on the origin of coal bed methane (CH4) in the Sydney and Bowen Basins of Australia (Smith and Pallasser, 1996), together with a totally erroneous description of the conclusions we drew from our data. Due to their error, the detailed discussion, Fig. 2 and Table 1 provided by Boreham et al. (199...

British Columbia exports about 25 million tonnes per year of metallurgical coal from two coalfields, which follow the Rocky Mountains along the eastern edge of the Province. In the north there are two mines in the Peace River coal&Id and in the south, five mines in the east Kootenay coalfields (Figure I). The east Kootenay coalfields are divided into the Elk Valley, Crowsnest and Flathead field...