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Development of a new injection system for gas-liquid reactions
40A studies. Failure in the rock mass, the grout, or the bar has been examined. Several methods of estimation of uplift capacity have been investigated. A uniform design methodology has been outlined, material properties specified, and examples of application of the method presented. 941315 Numerical analysis of the effectiveness of reinforcement methods at the Kristineberg Mine in Sweden Rosengren, L; Board, M; Krauland, N; Sandstrom, S Proc International Symposium on Rock Support, Sudbary, 1619 June 1992 P507-514. Publ Rotterdam: A A Balkema, 1992 The numerical model using the UDEC code for support design in the Kristineberg mine is applied to evaluate rock mass and support performance for different support alternatives. Parametric analysis of effects of bolt spacing, length, and diameter is carried out to assist in support optimisation.
Direct rock support methods See also: 941067 941316 Evaluation and selection of a shield support for high production Iongwall mining Zabrasky, C E; Peng, S S; Chiang, H S J Min Metal Fuels V40, N12, Dec 1992, P448-459 An opportunity to examine the performance of a range of shield support types arose in the Cumberland Mine, Pennsylvania, when existing supports were replaced due to old age and changing geological conditions. The major parameters on which supports were assessed are supporting efficiency, roof to floor convergence, active horizontal force, roof cavity, canopy contact condition, uniformity of support loads, and leg resistances. Different types may be specified within the same face but major characteristics should be as close as possible. 941317 Measured response of the immediate hangingwall of a Merensky Reef stope supported by cluster-stick packs only Kotze, T J Proc Symposium on Rock Engineering Problems Related to Hard Rock Mining at Shallow to Intermediate Depth, Rustenburg, 4-5 March 1993 P38-43. Publ Orange Grove." SANGORM, 1993 Pillar support at Impala Platinum's Merensky Reef operations utilises primary dip barriers and a secondary system of small pillars to support the immediate hanging wall. As the small pillars impede production efficiency, their replacement by adoption of restricted mining span and appropriate timber support was examined at one stope. Convergence meters and extensometers were installed at the stope. Recorded behaviour is described and discussed. The initial alternative support procedure was not wholly sucessful.
Grouting 941318 Development of a new injection system for gas-4iqnid reactions Shimada, S In: Soil Improvement (Current Japanese M a t e r i ~ ResearchVolume 9) P183-196. Publ London: Elsevier Applied Science, 1992 A chemical grouting technique using carbon dioxide gas as the hardening agent to react with sodium silicate is described. The Carbo-Rock System has environmental advantages over use of
normal gelling agents. The critical components of the system are the carbon dioxide controller, which governs gas/silicate mixing, and the carbon dioxide monitor, stationed at the injection monitor. The development of the injection equipment, operational sequences, laboratory test data on grouted soils, and results from field testing in sandy and silty sand soils are presented.
Reinforced earth See also." 941278, 941279, 941338, 941363, 941364
941319 Effects of soils and mixing conditions on bond strength between soil-cement and steel Kunito, T; Mashima, M In: Soil Improvement (Current Japanese Materials ResearchVolume 9) P167-181. Publ London: Elsevier Applied Science, 1992 Retaining walls of soil-cement columns require reinforcement by steel sections to carry heavy loads. Where the steel members are subject to vertical loads, the steel/soil-cement bond strength is important to performance of the wall. A series of tests has been carried out to provide quantitative data on the bond strength between round bar and flat plate reinforcement and column material for a range of soil-cement mixtures, and to investigate the relation between bond strength and compressive strength of the material. Design advice is given.
941320 Interaction of iateritic soil and steel grid reinforcement. Note Bergado, D T; Macatol, K C; Amin, N U; Chai, J C; Alfaro, M C Can Geoteeh J V30, N2, April 1993, P376-384 Pullout tests on welded steel grids in lateritic residual soils were carried out in the laboratory at various mesh geometries, reinforcement sizes, normal pressures, and compaction conditions and in the field under typical conditions of application. Longitudinal members contributed 8-15% of total resistance, passive resistance mobilized in front of transverse members the remainder. Maximum pullout resistance is represented by a bilinear curve similar to the failure envelope during direct shear tests of the backfill. Prediction of pullout resistance on the basis of this work is discussed.
941321 Ultimate bearing capacity of rectangular foundations on geogrid-reinforced sand. Technical note Omar M T; Dos, B M; Yen, S C; Purl, V K; Cook, E E Geoteeh Test J VI6, N2, June 1993, P246-252 Model tests were carried out with rectangular surface foundations on sand compacted to a constant value of relative density. The same geogrid and intergrid layer spacing were used all tests. The number of geogrid layers,the length to width ratio of the foundation, and the ratio of foundation width to size of the geogrid layers were varied. Based on the test results, the maximum required depth of reinforcement and size of geogrid layers to obtain maximum bearing capacity arc evaluated.
Direct rock support methods See also: 941067 941316 Evaluation and selection of a shield support for high production Iongwall mining Zabrasky, C E; Peng, S S; Chiang, H S J Min Metal Fuels V40, N12, Dec 1992, P448-459 An opportunity to examine the performance of a range of shield support types arose in the Cumberland Mine, Pennsylvania, when existing supports were replaced due to old age and changing geological conditions. The major parameters on which supports were assessed are supporting efficiency, roof to floor convergence, active horizontal force, roof cavity, canopy contact condition, uniformity of support loads, and leg resistances. Different types may be specified within the same face but major characteristics should be as close as possible. 941317 Measured response of the immediate hangingwall of a Merensky Reef stope supported by cluster-stick packs only Kotze, T J Proc Symposium on Rock Engineering Problems Related to Hard Rock Mining at Shallow to Intermediate Depth, Rustenburg, 4-5 March 1993 P38-43. Publ Orange Grove." SANGORM, 1993 Pillar support at Impala Platinum's Merensky Reef operations utilises primary dip barriers and a secondary system of small pillars to support the immediate hanging wall. As the small pillars impede production efficiency, their replacement by adoption of restricted mining span and appropriate timber support was examined at one stope. Convergence meters and extensometers were installed at the stope. Recorded behaviour is described and discussed. The initial alternative support procedure was not wholly sucessful.
Grouting 941318 Development of a new injection system for gas-4iqnid reactions Shimada, S In: Soil Improvement (Current Japanese M a t e r i ~ ResearchVolume 9) P183-196. Publ London: Elsevier Applied Science, 1992 A chemical grouting technique using carbon dioxide gas as the hardening agent to react with sodium silicate is described. The Carbo-Rock System has environmental advantages over use of
normal gelling agents. The critical components of the system are the carbon dioxide controller, which governs gas/silicate mixing, and the carbon dioxide monitor, stationed at the injection monitor. The development of the injection equipment, operational sequences, laboratory test data on grouted soils, and results from field testing in sandy and silty sand soils are presented.
Reinforced earth See also." 941278, 941279, 941338, 941363, 941364
941319 Effects of soils and mixing conditions on bond strength between soil-cement and steel Kunito, T; Mashima, M In: Soil Improvement (Current Japanese Materials ResearchVolume 9) P167-181. Publ London: Elsevier Applied Science, 1992 Retaining walls of soil-cement columns require reinforcement by steel sections to carry heavy loads. Where the steel members are subject to vertical loads, the steel/soil-cement bond strength is important to performance of the wall. A series of tests has been carried out to provide quantitative data on the bond strength between round bar and flat plate reinforcement and column material for a range of soil-cement mixtures, and to investigate the relation between bond strength and compressive strength of the material. Design advice is given.
941320 Interaction of iateritic soil and steel grid reinforcement. Note Bergado, D T; Macatol, K C; Amin, N U; Chai, J C; Alfaro, M C Can Geoteeh J V30, N2, April 1993, P376-384 Pullout tests on welded steel grids in lateritic residual soils were carried out in the laboratory at various mesh geometries, reinforcement sizes, normal pressures, and compaction conditions and in the field under typical conditions of application. Longitudinal members contributed 8-15% of total resistance, passive resistance mobilized in front of transverse members the remainder. Maximum pullout resistance is represented by a bilinear curve similar to the failure envelope during direct shear tests of the backfill. Prediction of pullout resistance on the basis of this work is discussed.
941321 Ultimate bearing capacity of rectangular foundations on geogrid-reinforced sand. Technical note Omar M T; Dos, B M; Yen, S C; Purl, V K; Cook, E E Geoteeh Test J VI6, N2, June 1993, P246-252 Model tests were carried out with rectangular surface foundations on sand compacted to a constant value of relative density. The same geogrid and intergrid layer spacing were used all tests. The number of geogrid layers,the length to width ratio of the foundation, and the ratio of foundation width to size of the geogrid layers were varied. Based on the test results, the maximum required depth of reinforcement and size of geogrid layers to obtain maximum bearing capacity arc evaluated.