Centrifuge tests of the uplift capacity of anchors

Rock and Soil Improvement Techniques Bolts and anchors 833239 ~;eILIm.TIOR ,0F ROCK ~,[CAVATIOh'S USING ROCK REINFOEC~4EhT Lang, T A; Bischoff, J A Proc 23rd ?ymposi~ on Rock Mechanics, Berkeley, 25-27 August 1982, P935-9~. Pub]. New York: AIME, 1982 Equations are presented to describe the conditions for stability of the rock bolt reinforced zone of the roof of an und~ground opening as a structural (beam-arch) member co,misting of reinforced rock units. A r,inforced rock unit consists of 8 rock bolt and the rock i~ediately surrounding and adjacent to it. The equations provide a basis for optimal design and installation of ~ rock bolt reinforcement system. 833240 ROCK SLOFE REINFORCEMENT WITH PASSIVE ANCHORS Moore, D P; Lewis, ~4 R Proc 23rd Symposium on Rock Mee_hanlcs, Berkeley~ 25-27 August 1982, Ix~5-952. Publ Ne~- York: A_~4E, 1982 Untensioned, fully grouted, steel bars (dowels) up to 30m long and 45mm in diameter were used to reinforce rock slopes several hlh-zlred metres high, excavated for a hydroelectric project near Revelstoke, British Columbia. These dowels were successfully used to prevent m~rface rock from loosening, to prevent sliding on Imtercormected discontinuities and to prevent sliding of relatively intact rock on a thin shear zone. Because the interaction between rOck slopes and dowels is not well u r ~ s t o o d , critical slopes were extensively monitored. 833241 NE~ L~OAqTORY INSTRbV.~NTATION FOE THE EVALUATION OF ROCK BOLT BEHAVIOR unal, E; Hardy, H R; Bienlawskl, Z T Proc 23rd Symposium on Reck Mechanics, Berkeley, 25-27 AugUst 1982, P985-995. Publ Ne~ York: A~.~, 1982 Describes a rock bolt testing facility for the evaluation of bolt-rock interaction. The instrumentation system, test procedures and typical results are ;resented. Seven anchorage-testing parameters and the associated acoustic emission were monitored during the experiments. 8332&2 CENTRIFUGE TEST~ OF THE UPLIFT CAPACITY OF ANCHORS Krebs Ovesen, N Proc lOth International Conference on Soil Mechanics and Foundstion Engineering, ~tockholm, 15-19 June 1981, VI, I~17-722. Publ Rotterdam: i. A. Balkeme, 1981 Investigates the scaling law relationship in model tests for the determination of uplif~ capacity of anchor slabs in sand. It is concluded that in centrifuge tests scale errors can be eliminated unlike in conventional model tests. On the basis of results from centrifuge tests formulae are devised for the uplift capacity of circular and square anchor slabs in sand pulled in ~ vertical and a slanting direction.

Grouting 833243 GROUTING FOR DAMS AND T U ~ T ~ L Ke~d, ~: F Int Water Power Dam Constr, V3h, }~, !.?_~y198Z,

~0 A brief stm~ery of papers presented at the Grouting in Geotechnlcal Engineering Conference, held in the USA, February 1982.

Groundwater control 8 3 3 2 ~ ROLE OF BENTONITE IN SOIL SE%IING APPLICLTION3 Alther, G R Bull AssOc Engrg Geol, Vlg, Nh, Nov 1982, Ph01-

4o9 Describes the use of bentonite as a natural soil sealant. Contamination of ground water by leachate from industrial waste sites in soils of high permeability may be prevented by the admixing of swelling bentonite at 5-15 per cent. Bentonite is also used in slurry trenches and cut off walls to provide impermeable barriers to ground water. 833245 LABG~ATORY TESTING OF VERTICAL DRAINS den Hoedt, G Proc 10th International Conference on So~l Mechanics and Foundation Engineering, StOckholm, 15-19 June 1981, V1, P627-630. Publ Rotterdam: A. A. Balkema, 1981 Important properties in the prediction of the performance of a vertical drain are: dischsrge capacity (urger lateral pressure) both initially and during prolonged use, filter function, and tensile strength. The Enka drain tester has been used to test discharge capacity and filter function. It is concluded that a suitable discharge capacity in the field would be l0 litres per hour, and that the filter Jacket of the drain should allow the passage of fine soll particles, forming a natural filter around the drain and thus increasing the effective radius of the drain.

833246 SAND

DRAIN MODEL BY CENTRAL DRAIN O ~ Prawono, S Proc lOth International Conference on Soil Mechanics and Foundation Engineering,

stockholm, 15-19 June 1981, Vl, F745-750. Publ Rotterdam: A. A. Balkema, 1981 Laboratory tests were conducted on soft clay samples to evaluate the coefficient of vertical consolidation for radial drainage. Coefficients were derived from compression-tlme curves in lever-srm and Bishop oedometer tests, and from pore pressure dissipation curves in ROwe oedometer tests. Comparison of results with Bsrron's theory of consolidation indicated that the theory could Ire'edict excess pore pressures and average degrees of consolidation with reasonable accuracy. Results from the Rowe oedometer tests were more consistent with the theory.

833247 SOME ASPECTS OF SAND-DRAINED GROUND Zeng, Q X; Wang, T R; Gu, Y Z Proe iOth International Conference on Soil Mechanics and Fotmdation Er~neering, Stockholm, 15-19 June 1981, VI, F835-838. Publ Rotterdam: A. A. Balkema, 1981