Rock bolts

Rock bolts

203A reinforcement increased both the drained shear strength and the secant deformation modulus of the reinforced sample. The results of a radiograph...

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203A

reinforcement increased both the drained shear strength and the secant deformation modulus of the reinforced sample. The results of a radiographic investigation are also presented, which indicate the mechanism of the strength enhancement to be one of radial strain control, arising from shear stresses mobilized on the soil-reinforcement interface. The experimental results are compared with a theoretical model.

836296 R E ~ T S ~

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OF m m m ~ B O U ~ ~STS FOR ~ m R m ~ O R C ~

OF ~ m USE OF ~ Y O~ ~ K R~

The paper describes methods of pregroutlng to prevent water inrush and to stabilize shaft sidewalls. It is concluded that the cost of preventive grouting operations is small in comparison with the overall expense of shaft-sinking operations and the cost of unproductive standing time. 836302 RESIN-ASSIb-rKu CONSOLIDATION DURING COLLIERY CONSTRUCTION IN THE %~STERN DONgASS (IN RUSSIAN) Davydov, V V Shakhtnoe stroit, N~, April 1983, P22-25

ROCXS (IN POLISH) Szwedzlcki, T; Zakrzowskl, J Przegl Gorn, V39, N2, Feb 1983, P59-63 The results of tests on the reinforcement of fractured rocks using polyurethanes carried out in the roof of a working longwall face and a roadway are given. 836297 INFLUENCING A ROCK MASSIF IN ORDER TO SECURE THE STABILITY OF MINE WORK-fNGS AT GREAT DKwI'HS (IN CZECH) Odstrcilik, Z Uhli, V30, N12, Dec 1982, P473-476 Describes two systems for increasing the stability of long mine workings: the injection of chemicals to strengthen the rock and the drilling of de-stressing hcles.

Bolts and anchors See also: 836115

The preparation on site of carbamlde with ferrous chloride resins, which will adhere to cement or alkaline rock, is described. These are then inJected into 42nmm holes to a depth of 1.5-2m. 836303 SOIL I M P R O V ~ METHOD UTILIZING A HIGH S~'~D WATER AND AIR JET ON THE DEVELOI~,~ENT AND APPLICATION OF COLU}~NAR SOLIDIFIED CONSTRUCTION ~OD

( c o u ~ JET ~-T~OD)

Yahiro, T; Yoshida, H; Nishi, .K In: Sixth International Symposium on Jet Cutting Technology, University of ~urrey, 6-8 April 1982, P397-h27. Publ Cr~nfield: BHRA, 1982 Describes the development and application of the 'column Jet pile method' developed to improve foundation soil. In the method a solidified grout colt~nn is farmed by injecting grout into a void farmed simultaneously by a high velocity air surround water Jet. The method prevents subsidence and contamination of groundwater. Examples of its use for building foundations are

given. 836298 ROCK BOLTS Min Mag, V149, NI, July 1983, F38-$7

Freezing A review of rock bolting systems available for the control of ground movement and prevention of rock falls around underground excavations. Systems mentioned are: mechanical expansion anchors, resin capsule grouting, mortar anchors, cable bolts and mechanical full colunm anchors.

836299 EXPLOSIVE ROOFBOLTS (IN RUSSIAN) Borodina, E N Shakhtnoe Stroit, N4, April 1983, P26-28 Tubular bolts packed with explosive and clay plugs are drilled into the roof at the same time as the preparation of the heading face for shotfiring. Tube steel of medium ultimate tensile strength (250MPa) should be used and wall thickness should be 3-3.5mm for use in mudstone and coal, 4-Smm in sandstone and limestone.

Grouting

83630~ FREEZING OF SOILS (IN FRENCH) Tot naghl, R Rev FT Geotech, N2!, Nov 1982, P5-29 Effects of natursl freeze and tha~ of soils have been studied for a long time, especially in northern countries. By use of artificial freezing it is possible to use these effects for solving engineering problems. The theoretical principles of artificial freezing are reviewed together with methods of freezing. Examples are given of the application of this technique.

Site Investigation and Field Observation See also: 836029, 836048, 836158

936300 GROUTING - MORE THAN MEETS THE EYE Jones, M B Tunn Tunnlg, VlS, NT, July 1983, I~i-43 A brief review of current grouting technology: types of grout available, grouting equipment and applications. ~36301 ASPECPS OF ADVANCED GROUTING DURIq~ SHAFT SINKING IN SOUTH AFRICA Dietz, H K O Int J Mine Water, N2, June 1982, P19-28

836305 INSTALLATION OF SKALLOW SAND-PACKED PIEZOMETERS IN LOOSE SATURATED SEDIMENT Garrett, M K; Carter, V Ground Water, V21, N3, May-June 1983, P354-355 Discusses problems encountered in hand installation of sand-packed piezometers in loose sand below the water table. Smccessful installation was achieved by freezing the piezcmeter and sand pack together.