189A
to investigate the support performsmce of hydraulic backfill. A mathematical model was developed for two vertically adjacent stopes separated by a sill pillar. Computer results included a complete history of slope closure and pillar stresses throughout the mining sequence. With the mining sequence and rock properties held constant, three separate analyses were made using varying backfill properties. Results of these analyses show decreases in stope closure and pillar stresses as the backfill quality increases, thus reducing the possible occurrence of rockbursts. 1866 M31OSZ~WSKI, J Effect of the interaction between supports and the rock mass on load.bearing capacity. In Polish. PRZEGL .GORN.VS0,N2,FEB. 1974, Pl07-116. The interaction between supports and the rock mass has a funaam~ntal influence on the load-bearing capacity in horizontal workings. This interaction may be either active or passive. The rate of Increase in load.bearlng capacity is accepted as a measure of this interaction and values are given for different conditions and configurations of mine roadw~ys.
Geological factors of importance in underground excavations 157 JONES, L GAROT, J The problem of siting underground cavities. In French. Figs. ACAD.ROY.SCIENCES D'OUTRE-M~,BULL.DES SEANCES, N4, 1972,P576-585.
Construction methods See also abstracts: 1908,1909.
1868 ~DRRISON, RG RUSSELL,pL SelectIng a mining method-rock mechenics, other factors. In SME Mining Engineering Handbook, Section 9. SOC .MIN. ~ G R S .AIME, NE~ YORK, VI,1973, P2-22. The factors that affect the selection of a mining method which is physically, economically and environmentally adaptable to recoverIng a mlueral from a de. posit are listed. Most surface and underground mining methods are related to these parameters from the rock mechanics design concept.
1869 RUSSELL, PL Nuclear-device mining systems. In SME Mining Engineering Hendbook, Section 21.i0. SOC .MIN. ENGRS. AIME, NEW YORK, V2,1973, P96-106. Nuclear explosives are described, available cost data is presented and a n u ~ e r of potential applications are discUssed. 1870 ANONYFDUS An efficient ripping operation at Monktonhall. 1F. MINE AND QUARRY,V3,N6,JUNE,197h,P9.
1871 LENZ,T KNIC~,W Shaft-slnking methods in the W. German coal mining industry. In German. GLUCK~UF,V] I_0,NIO,M~Y, 1974, P367-369 • Conventional shaft-slnking methods and those employed in special conditions such as waterlogged or running strata are briefly described. Shaft linings are also cons Idered. 1872 IDJ~S,J Possibility of working a thick coal seam in descending lifts under reconsolidated caved rocks. In Polish. PRZEGL.GORN .V30, N2, FEB. 1974, P93-99. A series of tests are reported to examine the possibility of working the lower layer of a thick seam under a roof formed from reconsolld~ted caved rocks. The tests include: strength index tests; disintegration tests In water of rock from the caved area; convergence measurements; and laboratory model tests.
1873 W~SCH, B Driving of roadwsys using drilling and blasting. In German. GLUCK~UF,VIIO, NI0, M~Y.1974, P37 ~-382.
Influenceof dynamic loads due to explosions or earthquakes 7 871, ~ISIKS,EG REDEL, C Geologic and seismic considerations on the Caracas Metro. In Spanish. Proc.hth Venezuelan Geological Congress .Figs. DIR. G~DL.BDL .G~DL. PUBL .ESPECI ~L, CARACA S, V5, N5,1972, P2913- 2928. 1875 DVOR ~K, Determination of allowable explosive charges in the proximity of tunnels. In German. ~OF,5R. ROCK MECHANICS, SUPPL. 3, JUNE, 197h, P~ 3 i- 142. Using a method suitable for calculating the correct explosive charge for use in underground openings, two problems are considered: blasting in an open excavation pit and driving a tunnel, both close To another tunnel or gallery. Data are given for the determination of Zones within which a certain degree of damage to a tunnel can be expected.
Experimental and numerical techniques 1876 JOHNSON, OA performance and cost model for underground drilling and blasting. Proc. 12th Symposium on the applications of computers and mathematics in the minerals industry, Golden, Colo.Apr.]974. COLOR ~DO SCH.MINES, GOLD~,USA,V2, ~97h,P.G95-GI52. A performance and cost model that describes percussive drilling and blasting has been developed for underground stoplng and drifting situations. It predicts performance and costs from input such as mine design variables, machine parameters and physical rock properties.