نتایج جستجو برای: Caved Material System
تعداد نتایج: 2532223 فیلتر نتایج به سال:
Estimation of the height of caved and fractured zones above a longwall panel along with the stability conditions of the goaf area are very crucial to determine the abutment stresses, ground subsidence, and face support as well as designing the surrounding gates and intervening pillars. In this work, the height of caving-fracturing zone above the mined panel is considered as the height of destre...
Two confined pillar tests were conducted at the Kiirunavaara mine to investigate the degree of compaction of three materials, i.e., 0–32-mm backfilled material, a blend of ore and waste material and caved material. Two blastholes were drilled parallel to each pillar wall, and several measurement holes were drilled in between the blastholes through each pillar. Both the measurement holes and bac...
In any cave mining method a horizontal slice of rock is mined out at the base of the block to be caved by drilling and blasting. Once a sufficiently large area has been mined continuous caving initiates and propagates through the block. High stress levels are set up in the abutment zone around the perimeter of the caving area that can affect tunnel stability to a distance of 20 metres from the ...
Eighty two patients with an endoscopically healed gastric ulcer, were treated for two years with either Caved-S tablets, two twice daily or cimetidine 400 mg at night. During the first year, 12% (four out of 34) of the Caved-S group and 10% (four out of 41) of the cimetidine group had an ulcer recurrence. By the end of the second year, the recurrence rate was 29% (nine out of 31) in the Caved-S...
The cavability assessment of rock mass cavability and indicating the damage profile ahead of a cave-back is of great importance in the evaluation of a caving mine operation, which can influence all aspects of the mine operation. Due to the lack of access to the caved zones, our current knowledge about the damage profile in caved zones is very limited. Among the different approaches available, p...
One hundred patients with benign gastric ulceration were treated in a single-blind, endoscopically controlled trial to assess the relative efficacy of cimetidine (1 g daily) and Caved-S (six tablets daily). Ulcer healing was assessed after six weeks' treatment, and, if incomplete, after a further six weeks. There was no significant difference between the two drug regimens (approximately 63% at ...
We provide in this paper a pair of properties that are both necessary and sufficient to characterize the domain of single-peaked preference profiles. This characterization allows for a definition of single-peaked preference profiles without using an ad-hoc unlerlying order of the alternatives and also sheds light on the structure of single-peaked profiles. Considering the larger domain of value...
Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the a...
2020 is the year when 40% of 4,000-year-old Milne Ice Shelf, located on north-western edge Ellesmere Island, caved into sea. Greenland Sheet has already passed point no return. human presence in Arctic Ocean fell dramatically due …
The geomechanical model is proposed and the technology of numerical simulation developed. Carried out computer state being undermined repeatedly rock massifs 3 rd potash level Starobin deposit taking into account its structural strength features, as well technological schemes primary mining. regularities stress-strain zones formation in mass containing mined mine workings inter-panel pillars we...
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