Selecting the right shield support

Selecting the right shield support

41A 911319 Calculation of deep rigid rectangular anchor slabs Bosakov, S V Soil Much Found Engng V26, N5, Sept-Oct 1989, P214-217 The problem of a de...

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41A 911319 Calculation of deep rigid rectangular anchor slabs Bosakov, S V

Soil Much Found Engng V26, N5, Sept-Oct 1989, P214-217 The problem of a deep rigid rectangular anchor reduces to that of a rectangular plate pressed against the boundary of a rectangular slot in a semi-infinite elastic solid. A solution based on Zemochkin's method and the truncation method is presented. Contact stresses and linear displacements are evaluated for slabs with aspect ratios 1-4.

911320 Innovative mechano-ehemical anchor development and application Moore, R K

Proc Symposium on Advances in Rock Met&talcs in Underground Coal Mining, Witbunk, 12 Sept 1989 P101-103. Publ Marshailtown: SANGORM, 1989 Optimisation of roof support systems in underground coal mines has been a challenge since earliest times. The stratified nature of overlying rocks, the long term use of the supported roadways, and the presence of faults, igneous intrusions and their effect on natural stress levels combine to make the selection of the optimum rock support system difficult. Latest developments in roof support systems in the context of both the materials science and the background rock mechanics principles used are discussed. The Sandex anchor system, a full column anchored bolt in a capsule of special high friction granular aggregates and grout, is described.

911321 Support requirements during shaft sinking operations at 10 shaft Vaal Reefs Exploration & Mining Co Ltd Harris, B A; Akermann, K A

Proc Symposium on Rock Instability Problems in Mine Shafts, Potchefstroom,lO May 1990 P1-5. Publ Marshalltown: SANGORM, 1990 During shaft sinking operations, sidewall support requirements vary according to the rockmass condition. The competency of a rockmass influences the support requirements, the design of which is very dependent on the stress regime present. The varying conditions encountered during sinking operations for the 10 shaft system are described, together with support used, which ranged from simple spot bolting to pattern bolting with expanded metal sheets in heavily fractured ground.

911322 Ground control problems during the sinking of a deep level subshaft Leach, A R

Proc Symposium on Rock Instability Problems in Mine Shafts, Potckefstroom,lO May 1990 P7-14. Publ Marshaiitown: SANGO RM, 1990 During the initial stages of shaft sinking at South mine, the support for the shaft sidewalls comprised only shepherds crook rebars, with the lining being cast some 20 metres from the shaft bottom. It soon became apparent that this was inadequate as intense stress fracturing in the sidewalls was causing poor ground conditions. An expanded metal mesh and split set system was adopted, with improvements resulting in safety, ground control, and shaft sinking rate.

911323 Investigation into the optimization of a shotcrete cable bolt support system Hassani, F; Rajaie, H

Minerals, Materials and Industry, Proc ldth Congress of the Council of Mining and Metalhwgical institatioas, Ediaburgk, 2-6 July 1990 P119-129. Publ IMM: London, 1990 Fully grouted, untensioned cables have been used extensively for reinforcement of surface and underground rock excavations. Investigations related to the development and use of shotcrete in the installation of cable bolts are presented. The unique yielding behaviour of this type of cable bolt, together with its high peak and residual load bearing capacity compared with conventional cable support, is demonstrated. The effect of aggregate-cement ratio and water-cement ratio of the shotcrete on bonding properties are evaluated and discussed.

Direct rock support methods See also: 911432, 911439

911324 Selecting the right shield support Barczak, T M

Engug Min J V191, NS, May 1990, P36-43 Evolution of face supports from the simple chock to current powered shields is described briefly. Trends in application of shield support in the USA are illustrated. Characteristics of 2and 4-leg powered supports and shield and strata interaction are discussed, Abilities of shields under unstable roof conditions, automation technology, and capacity considerations are addressed. Expected developments in shield design, with increasing width, support monitoring, and automation are considered.

911325 Non-linear finite-element-method model for calculating yielding arch supports in conimining (In German) Beckman, D; Klein, J; Weise, A

Giuckauf-forschangsk VSI, N4, Aug 1990. P179-183 Yielding arch supports are very widely used in coal mine roadways. A PC based finite element simulation of yielding arch behaviour has been developed as a design tool. It includes nonlinearity of large strain deformation of sliding components of the support, and of bedding of support base units. The philosophy behind the model is discussed and some results presented.

911326 Powered supports - the current status Smart, G D; Holland, C J; Benfold, G W

J Mia Metal Fuel V37, N6/7, June,July 1989, P283-288 Powered supports make a major contribution to the success of longwall mining. Support configurations are described and specific factors to be considered at the selection stage are listed. Development of reaction between the roof and floor during setting and the production cycle is examined, together with electrohydraulic control systems. Trend worldwide appears to be towards higher rated supports with immediate forward support (IFS), long canopy design.

© 1991 Pergamon Press plc. Reproduction not permitted