A method is given for calculating the amount of rock broken and the daily advance of an AM-50 drifting machine.
786179 INVESTIG~ION OF THE EFFECTS OF HARDENED WASHERS ON THE UNIFORMITY OF ROOF BOLT TENSION AND RESULTING GROUND CONTROL IN AN UND~GROUND M I ~ Rosso, R S
786172 PROBLEMS OF DISINTEGRATION OF ROCK BY DRIVAGE MACHINES. PART I. EVALUATION OF ROCK PROPERTIES WITH THE AIM OF ~EAKING THE ROCKS D U R I ~ DRIVAGE OF LONG MINING AND UNDERGROUND ENGINEERING WORKINGS (IN CZECH) Vasek, J Uhll, 725, NT, July 1977, P271-280 Indicates the rock properties it is necessary to know when selecting a method of drivage.
Rock and Soil Improvement Techniques 786173 PERMEABLE SYNTHETICFABRIC M~MBRANES 1. THEIR USE IN THE STRENGTHENING OF SOILS Hoare, D J Ground Engng, Vll, N5, July 1978, P33-36 Considers the mechanisms by which fabrics strengthen soil. Two main classes of use are defined: (i) to improve bearing capacity, and (2) to act as an earth retaining structure. Examples of these are reviewed. 22 refs. 786174 COMPACTING AND STABILIZATION OF SEITLING GROUNDS IN RESIDENTIAL AND INDUSTRIAL CONSEUCTION (IN RUSSIAN) Litvlnov, I M Kiev: Bt*livelnik, 1977, 288P
Bolts and anchors
USBM OFR ~0-78, Oct 1977, 189P The complete roof bolt installation amd roof bolt loads, mine convergence, and bed separation were monitored for a period of 5 months. The results show no evidence to support or to refute the theory that mechanical roof bolts offer better support when they are installed with a high uniformity of tension. It is also shown that if the bolts are installed with a maximum deviation from the mean torque of + or - 15 per cent, the addition of hardened washers significantly improved the uniformity of the installed tensions in the roof bolts. Avail: NTIS, Slrir~ield, Va, 22161, USA
(~ 281656/~) 786180 UNIFORM FOUR-FOOT LENGTH SPLIT SET ROOF BOLTS VS. UNIFORM FOUR-FOOT LENGTH FULLY GROUTED RESIN ROOF BOLTS Maher, J US~M OFR 43-78, 31 Jan 1977, BvgP The fully grouted resin bolts were capable of abou% 2,0001b of anchorage per inch of grouted rebar and the split set roof bolts have anchorage capacities in the range of 125 to 3001b per inch of bolt in contact with the roof bolt hole. A study of the behaviour in an area bolted with split set roof bolts was compared with that in a similar area bolted with fully grouted resin bolts. In both areas nominal mine design parameters were the same with 4ft bolts at 4ft centres. Both systems functioned adequately to support blast damaged o~ otherwise fractured roof rock. Roof movement was less in the area bolted with the more yielding split set roof bolts. Test data and observations indicate this to be attributable to more competerfG roof strata resulting from proper and controlled blasting technique s.
786175 ANCHORING SUPPORTS OF 35-750 KV POWER LINES (IN
RU~) Vinogradov~ D E Moscow: Energiia, 1977, 89P 786176 RESIN ASSISTED BOLTING (IN RUSSIAN) Kara, V V Ugol Ukralr~, V21, N7, July 1977, P20-22 The technique of resin bolting is described and examples of schemes for its application on the face and at the ripping lip are given. 786177 DESIGN CRITERIA FOR ANCHOR CABLES AND BOLTING IN UNDERGROUND OPENINGS Manfredini, G; Martineth, S; Ribacchi, R In: Numerical Methods in Geomechamics (Papers to 2nd International Conference, Blacksburg, Va, June 1976), V2, P859-872. Publ New Yark, ASCE, 1976 786178 HOOK ANCHOR TESTS IN FROZEN AND UNFROZEN GROUND Kovac s, A US A r ~ Cold Regions Research amd Engineering Lab report SR 229, May 1975, SIP Avail: Irrls. Springfield, Va, 22161, USA (ADA
Avail: N~IS, Sl~ringfield, Va, 22161, USA (PB
281957/AS) Grouting 786181 PRINCIPLES AND APPLICATIONS OF GROUTIE~G Cambefort, H Q J Ergrg Geol, Vl0, N2, 1977, P57-95 Part i, Principles s immludes characteristics of grouts (foams, settlement, getting time, vlscosity-rlgldlty), flow of grouts in the soil (impreg~etion and claquage, lab tests, injection of fissures, injection of sands and gravels, limits of inJectability~ injection pressures), characteristics of injected soil (mechanical strength, permeability). Part 2, Applications, includes treatment of pressure tunnels, cavity filling and Jackimg-~p of buildings. 786182 GROUTING OF SOILS IN COLD ENVIRONMEE~S: A LITERATURE ~ A R C H Johnsonj R US Army Cold Regions Research and Engineering Lab report SR 77-42, Dec 1977, 49P A literature survey with 52 refs.