Rim failure at Premier mine

268A 895314 Three-dimensional analysis of locally loaded slopes Michalowski, R L Geoteclmique V39, NI. March 1989, P27-38 A 3-D slope stability analysis for drained frictional-cohesive material based on the upper-bound technique of limit analysis is presented. A rigid.block toe or above-the-toe collapse mechanism is considered, with energy dissipation along planar velocity discontinuities. The method can evaluate factor of safety or limit load applied to the slope. Results are compared with published values for a frictionless material, showing that, for a wide range of parameters, the analysis yields lower values of limit loads. Since there are rigorous upper bounds to the true limit load, results should be considered closer to the actual limit load. 895315 New analysis procedure to explain a slope failure at the Martin Lake mine Miller, T W; Hamilton, J M Geoteclmique V39, NI, March 1989, P107-123 The upper bound procedure has been applied to practical slope stability problems. The procedure is generalised to include effective stress calculations with variable pore pressure conditions, and gives a general failure mechanism which includes both rigid body motion and continuous deformations. The mechanism was developed to explain slope failure at a lignite mine. Predictions here and comparisons with published results show the new mechanism can improve predictions of slope stability. 895316 Rock slopes: stabilization and remedial measures against degradation in weathered and fresh rock Fookes, P G; Weltman, A J Proc Instn Civ Engrs Part 1 1186. April 1989, t>359-380 Weathering and erosion processes which may affect rock slopes are described and remedial measures discussed, including geotextiles, mesh, shotcrete, gabion walling, crib walling, dentition, anchored beams, bolts,and drainage. Guidelines for the selection of the appropriate method, including the controlling factors of rock weathering grades, joint spacing, and slope height, are presented. Typical unit costs and design charts for the construction of rock trap ditches and fences are given. 895317 Erosion losses from the surfaces of gold-tailings dams Blight, G E J S Afr lnst Min Metall V89, NI, Jan 1989, P23-29 Erosion losses from the slopes and horizontal top surfaces of gold tailings dams were monitored over a 4 year period. Variables affecting the rate of erosion, surface strength, slope length and slope angle, are compared. Surface strength was measured using ETCOM penetration resistance and vane shear strength, and erosion loss by retreat of the slope. The horizontal top surfaces are relatively unaffected by erosion. Little correlation was found between slope variables and erosion loss. 895318 Measured and predicted stresses and bearing capacity of a full scale slope reinforced with nails Sawick, A; Lesniewska, D; Kulczykowski. M Soils Found 1128, N4, Dec 1988, P47-56 The mechanical behaviour of a steep slope reinforced with nails is analysed using the continuum mechanics approach. Soil nailing was applied to a steep slope of an excavation in

loose sand and the strains measured. A continuum elastic theory of reinforced soil is applied to predict the stresses in the reinforcement and the bearing capacity of a slope calculated on the basis of a rigid plastic model of reinforced soil and plastic limit theorems. Comparison of predicted and measured results shows reasonable agreement.

895319 Economic and technical relations between open pit mine design and equipment selection Lizotte, P Proc International Symposium on Mine Planning and Equipment Selection, Calgary, 3-4 November 1988 P3-13. Publ Rotterdam: A A Balkema, 1988 Most computer models for open pit design are based on a block model representation of the orebody and surrounding gangue. The block model is also amenable to storage of other information about the ore deposit, such as grade of mineral, proportion of ore types and fracture intensity. This information is used to produce a profit matrix. Design of the slope is important. Two methods may be used, definition of cone removal using analytical geometry, and block addressing. Equipment selection is discussed. The main economic and technical relations are mining costs, block dimensions and pit slopes. An example is given to illustrate simple open pit mine design.

895320 Rim failure at Premier mine Bartlett, P J; Raubenheimer, M Proc 1st Regional Conference for Africa, Rock Mechanics in Africa, Swaziland, 3-4 November 1988 P49-52. Publ Marshaltown." SANGORM, 1988 Two major collapses in the 350m high sidewalls of an open pit currently being deepened by underground mining are described. The sidewalls are composed of felsite. Rim and radial beacons are used to monitor movements in sidewalls and predict failure. One failure occurred after 15 weeks of horizontal movement. Mode of failure was toppling. The other failure occurred in an area of the mine which has shown constant movement. The area is bounded by 2 fault planes which form an unstable wedge of l0 million tonnes of rock. The toppling and wedge failure was predicted.

895321 Monitoring of planar slope failure in rockfill quarry, Glenbawn Dam Yolk, P L Proc Symposium on Soil Slope Instability and StabUisation, Sydney, 30 November-2 December 1987 P4ll-416. Pub/ Rotterdam: A A Balkema, 1987 A large tension crack appeared in a limestone and sandstone quarry developed to provide fill for the Glenbawn Dam. Movement of the sliding block along a thin weathered seam was monitored. Rate of movement appeared dependent on a combination of blasting and rainfall factors. A variety of remedial measures was suggested, but as the quarry was nearing the end of its life. an area at the base of the slope was cordoned off and work continued.

1989 Pergamon Press plc. Reproduction not permitted