Mathematical model for bore-injected cement grout installations

REINFORCEMENT:EARTH & GEOSYNTHETICS

ROCK AND SOIL REINFORCEMENT AND SUPPORT General 965264 Current capabilities for finite element analysis of geomechanics and structural support systems in underground mining A. Currie, D. Ho & J. Yang, in: Applications o f computers and operations research in the minerals industries. Conference, Brisbane, 1995, ed ANON (AusIMM), 1995, pp 507-514. This paper describes the capabilities provided by finite element graphics and analysis software for modelling and sequential investigation of both excavation and lining, or rock bolting, construction sequences. (from Authors) 965265 Reuse of coal mining wastes in civil engineering - part 2: utilization of minestone K. M. Skarzynska, Waste Management, 15(2), 1995, pp 83126. The oldest method of minestone utilization is reclamation of spoil heaps by adapting them to the landscape by afforestation or agricultural management. The best method is, however, complete removal of the wastes. Hence, for many years research has been carded out to find new ways of minestone utilization to minimize disposal cost and harmful environmental effects. Earth structures offer the best possibilities of minestone utilization. Investigations conducted in recent years in Germany, the UK, France, Belgium, the Netherlands and also in Poland have led to the use of many tonnes of wastes in the construction of road and railroad banks, river embankments, dykes and dams, filling of land depressions and open pits, as well as for sea wharfs and land reclamation. This paper presents descriptions of minestone applications to hydraulic, harbour and road engineering as well as to mine backfilling and restoration of derelict land. (from Author)

Bolts and anchors 965266 Automatic roof bolt strain monitoring in coal mines E. Layer, International Journal of Rock Mechanics & Mining Sciences, 33(1), 1996, pp 93-95. This paper describes a measuring system intended for strain monitoring in the bolts of roof bolting. The system fulfils requirements resulting from specific working conditions and environmental conditions which exist in most of the Polish coal mines. (Author)

Shotcrete 965267 Thames Tunnel shotcrete approved D. Fleming, New Civil Engineering (NCE), 1157, 1996, p 3. London Underground has been given planning permission to shotcrete the Thames Tunnel, the world's first underwater tunnel. But London Docklands Development Corporation has given this approval without having necessary design details from LU. Up to now it was expected that English Heritage and its consultants and would approve all details when LU submitted them. LDDC approval is conditional on LU preserving four arches and providing 'full structural details of the new lining, including the drainage system between the lining and the tunnel's primary brickwork'. Disagreement has emerged over use of a waterproof membrane with steel reinforce concrete. English Heritage's experts fear corrosion of steel reinforcement and prefer fibre reinfor-

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cement. And concerns were also raised over hacking away the original lining at critical structural locations. (from Author)

Direct rock support methods 965268 Characteristics and analysis of powered supports for sublevel caving method (in Chinese) Yu Haiyong, Wu Fengdong, Meng Jinsuo, Jin Zhixin &Yan Zhengyi, Journal - China Coal Society, 20(5), 1995, pp 461466. Based on the measured data the main characteristics of ground pressure in a sub-level caving face are as the following: 1) The working resistance of powered support is not greater than that of supports used in a single coal seam or in top slice of a coal seam; 2) The external load exerted on the support used in sub-level caving face generally moves forward. Therefore, in design and selection of powered support for sub-level caving method, attention should be given to the capacity of front end of canopy. (English summary)

Grouting 965269 A positive approach to grouting M. D. Johns, G. F. Norman & L. J. Smith, Proceedings ICE: Structures & Buildings, 110(4), 1995, pp 398-409. This paper describes the successful grouping of prestressing tendons on Taft Viaduct, part of the Butetown Link Road in Cardiff. Discussion of the grout's performance shows the relationship of water/cement ratio, admixtures and temperature to bleed, shrinkage and flow. Also, the practical problems associated with grouting of discontinuous internal ducts typical of a segmental structure are highlighted. (Authors) 965270 Aspects of compaction grouting of liquefiable soft R. W. Boulanger & R. F. Hayden, Journal o f Geotechnical Engineering - ASCE, 121(12), 1995, pp 844-855. The purpose of this paper is to review available case-history data on the treatment of liquefiable soils by compaction grouting, and to provide observations that are useful in evaluating the effectiveness of future compaction-grouting applications. Quantifying the composite behavior of a compaction-grouted soil mass requires an improved understanding of the treatment mechanisms. (from Authors) 965271 Mathematical model for bore-injected cement grout installations I. Kleyner & R. J. Krizek, Journal o f Geotechnical Engineering - ASCE, 121(11), 1995, pp 782-788. A mathematical model is developed for the physical process that occurs as grout consolidates under the applied pressure and expels its excess water into the surrounding soil under conditions of impeded drainage. The model is then used to calculate such parameters as the average degree of consolidation of the grout as a function of time prior to set and the change in the borehole radius. (from Authors)

Reinforced earth and geosynthetics 965272 Effect of stiffness and amount of reinforcement on strength of sand R. R. AI-Omari, Y. N. Nazhat & H. H. Dobaissi, Quarterly Journal o f Engineering Geology, 28(4), 1995, pp 363-367. Triaxial tests have been performed on plastic mesh reinforced sand. The sand density, mesh stiffness and the number of reinforcing layers were varied. From these tests it was