equations relating to the ~ o b l e m of flow through pc~ous media of a ali~htly compressible fluid, such as water, in systems: a) with cc~fime~ flow; b) with a free surface; c) where the flow is cor~imed to a uetwcrk of def~==ble fractures; d) where flow in the unsaturated region cannot be neglected.
See also abstract: 2127.
Groundwater See abstract :2002.
Chemical and physical changes due t o w a t e r 2007 TAB~, JJ FULTON, PF DABBOUS, MK Development of techniques ard the measurement of relative permeability and capillary pressure relationships in coal.BOF. US .BUR .MINES~ OFR, N22,1974 ,80P. In this study gas stud water permeabillties of a large m ~ b e r of samples from the Pittsburgh ard Pocahontas coals were measured at various overbt~den amd mean flow pressures. A wide variation in the air and water permeabilities was obtained fer each type of coal. Overburden l~esaure has the most significant effect on the sir~lephase permeability. Considerable hysteretlc effect was observed far both air amd water permeabilities. Gas permeabilities are affecte~ to a lesser degree by mean flow pressure above atmospheric. Tests were performed under steads-state conditions for both drainage amd inhibition cycles. Results i~x~icate that the flow of gas is greatly redfaced during %he latimer process s whereas it is largely u r ~ m ~ i s h e d over a wide watez~saturation range during draining.
Underground excavations 2oo8
2011 BLL~LEY, RE ZIMMER, PF Open pit mining. A review of the past five years~4F. MIN.CONGRESS J.V60, N2,1974,P30-35. The authars tmderline several basic factors which influenced the trends of open pit operations during the last five years. The existing operations and new ventures are generally now of lower grade and poorer quality ore with higher over-burden and stri~otng requirements. The new operations cor~ributed to ir~reased efficiency and l~Oductivity. The computerized approach to mine ~ r g ard design has evolved into a functional mamagement tool. Rock mechanics studies enabled the design of slopes which will oI~ timize the economics of the pit. Artificial stabilization techniques that are being used are: i. Rock backfill cr concrete buttress placed at the toe of the failing zones; 2. Rock boltimg; 3. Groutimg; 4. Freezing, 5. Electrochemical methods. One of the most striking developments is the i m p r i n t of the reliability and productivity of existing pit equipment. 2012 WANG, FD COLORAI~ SCHOOL OF MINES,GOLDEN, USA ROPCHAN, DM BUR. M!NES, DENVER, COLO, USA SUN,MC BUR.MINES, DENVER, CGLO, USA Proposed teahnique for improvimg coal-mine roof stability by pillar softening.12F,3T~llR. TRANS. SOC .MIN.ENGRS.AIMEjV256, NI, MARCH, 1974, P59-63 • A proposed technique far improving coal-mine roof stability by softening parts of coal pillars along the sides of entries developed from structural analysis, is presented. This technique is based on the tranaference of the high stress concentration in the roof near the upper corners of a rectangular opening to the roof rock and coal over the solid away from the opening. The technique is discussed and shown to be analytically sound and effectivej ar~ may also be useful for reducing tensile roof failure amd coal rib sloughir6. The authors consider the technique feasible~ end believe that it merits und~groumd trials.
MANUAL M ~ fcr placer mining. In Russian with abridged Emglish table of contents. Figs,Tabls,Refs. N~DRA, MOSCOW, 1973. The mac!n! includes the following sections : I. DredgiDg; 2. Placer mining; 3. Mine shafts; 4. Permafrost control; 5. Dust control; 6. Artificial thawing; 7. Blastir6; 8. Ventilation; 9. Drillir~; i0. Hydraulic Jets; ii. Open pit mining; 12. Excavating equipment; 13. Ttmnelling in permafrost. Mathematical formulae used in engineering geocryolegy and hydraulic Jet drilling are given. KC~, ~ QUEENS UNIV. KINGSTON, CDN Analysis amd prediction of stoping costs.Figs,Tabls, Refs. MSC THESIS, QUEENS UNIV.CANADA,1973.
2013 BARRIE~S,G WHITE PINE C O P F ~ C0.WHITE PINE,MICH.USA PARKER, J WHITE PINE C O P ~ C0.WHITE PINE, MICH.USA Use of the pressure arch in mine design at k~tite Pine. 17F,7R. TRANS. SCC.MIN. E~RS. AIME~V256, N1,MAR. i974,P75-82 • The moat realistic mine pillar design is based on observations a~d measurements in situ. Low-co~ reliable instrtm~ntation has made this approach possible. At the White Pine mine, with its thousands of pillars of all shapes and sizes u r ~ all kinds of loading corzlitions, practical pillar design criteria have been developed. The pressure arch theory is explained, and work in two test pamela of the mine is described. The pressure arch mechanism, which relies on lateral stress for support, can be applied to puzzling roof and pillar conditions in other mines.
2010 HA~O~D, GF QUEENS UNYV.KI~STON, CDN Cost mi~m~zatiou of blasthole stoping.Figs,Tabls, Refs. MSC THESIS, Q U ~ N S UNIV.CANADA,1973.
WALLWORK, GW Underground mlnir~ of coal. Review. MIN. CONGRESS J .V60#N2 #1974 ,i~9-90, 95. The co~l Irdustry faces a new eta. Mar~ difficulties