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Computer aids in rehabilitation of opencast mines
IliA design considerations and production work procedures are explained and are followed by a detailed comparison of the improvement obtained.
873208 Computer aids in rehabilitation of opencast mines Redman, A E; Kruger, L W; De Jager, A W Proc 2nd Group Mining Symposium, Johannesburg, Sept 1985 P13-18. Publ Johannesburg: Anglo American Corporation, 1985
Ground freezing
Interactive graphics programs can be of considerable use to the mine planner. Three dimensional maps can be made of overburden depth, coal thickness and bulking factor, and mining and post mining topography simulated. Each aspect can be viewed, changed and updated continually. Spoil levelling and soil replacement can be optimised by such modelling.
073205 Prevention of cracking and water leakage in the concrete inner fining of frozen shafts. Short communication Yu Gongchun lnt J Min Geoi Engng I,'4, N3, Oct 1986, P247-251 Coal deposits on both banks of the Huai River in the Anhui Province of the People's Republic of China are overlain by 200 to 400m of saturated Quaternary alluvium which contains clay, marl and uncemented sand, making shaft sinking impractical unless assisted by some form of ground freezing. Shaft sinking in frozen ground in China utilizes a double lining design/construction method. Because of the high temperature gradient in the concrete lining when this is formed by casting against the frozen ground, the consequent thermal stresses combined with stresses resulting from the shrinkage of the cast concrete often cause fissures or cracks in the shaft lining. Two examples are described to illustrate how cracking has been eliminated in several frozen shafts by developing this innovative double lining method.
8732O6 Ground freezing for soft ground shaft sinking Shuster, J A Proc of the 1985 Rapid Excavation and Tunneling Conference, New York, 16-20 June 1985 II2, P1046-1059. Publ New York: AIME, 1985 Case histories are reported for several soft ground shafts, ranging from 6ft to 40ft in diameter and 50ft to 230ft in overburden depth, for which ground freezing was employed to provide temporary ground support and groundwater control during shaft sinking through the overburden. Cases reported emphasized dealing with difficult site and ground conditions such as working within existing buildings, through very soft, running and bouldery soils, in the presence of substantial lateral groundwater flows, and into salt dome deposits requiring special considerations. Construction procedures, schedule, and relative costs are discussed for each case. Auth.
Surface Structures 873207 Planning criteria for open pit mines under special consideration of slope stability and controlled blasting Weise, H Proc 2nd Symposium in Ranchi, German Open Pit Mining, 21-22 No~ 1985 Paper B1, 13P. Essen: Giuckauf, 1985 Slope stability considerations are important in planning of open cast mines. The main factors to be taken into account are groundwater, geologic structures and rock mechanical properties, slope height, length and angle, and required slope stand time. Combinations of slope stability,angle and dimensions determine the extractable reserves. The use of controlled blasting to shatter consolidated material and permit the use of bucket wheel excavators is briefly considered.
Base courses and pavements 873209 Permeability of geotextile-included railroad bed under repeated load Saxena, S K; Hsu, T S Geotext Geomem V4, N1, 1986, P31-51 Geotextiles are used in railroad beds to separate ballast from subgrade fines and to stop migration of the soil fines. The change in permeability of a simulated railroad bed with time and with number of load applications has been studied in the laboratory. Permeability decreased, due to clogging of the soil fines in and around the textile, with increasing time and with the increase in the number of cycle of repeated load. Reasons for the pumping action are discussed. A sequence of processes for the clogging of the railbed is proposed. 873210 Geotextile reinforced unpaved logging roads: the effect of anchorage Douglas, R A; Kelly, M A Geotext Geomem I,'4, N2, 1986, P93-106 The use of geotextiles to reinforce unpaved roads is becoming common. The assumption that increasing the modulus of the geotextile will increase the stiffness of the road has been examined in large scale model tests. The results, in conjunction with previous work, indicate that geotextile modulus has no significant effect on overall road stiffness, for quasi-static strip load tests, whether the geotextiles are fully anchored or completely free at the edges. 873211 Mount Pleasant Airport, Falkland Islands: design Skeene, G; Brice, G J lnst Civ Engng Proc, Part 1 II82, Feb 1987, P77-96 The significant aspects of the design of the civil engineering works for Mount Pleasant Airport, Falkland Islands, are described. The works include a 2590m main runway, taxiways, aprons, and over 150 buildings with all the associated infrastructure required, on a green field site in a remote and arduous location. 873212 Stability of gravel sub-bases Earland, M G; Pike, D C Transport and Road Research Laboratory Research report N64, 1986, 17P A series of trafficking tests was part of a study of the stability of unbound granular sub-bases. Results of these tests were correlated with shear strengths measured in a 300ram shear box machine, modified to test wet aggregates with plastic fines. Estimates of the precision of this test were made. Many gravel sub-bases performed as well as crushed reck type 1 sub-bases.
© 1987 Pergamon Journals Ltd. Reproduction not permitted
873208 Computer aids in rehabilitation of opencast mines Redman, A E; Kruger, L W; De Jager, A W Proc 2nd Group Mining Symposium, Johannesburg, Sept 1985 P13-18. Publ Johannesburg: Anglo American Corporation, 1985
Ground freezing
Interactive graphics programs can be of considerable use to the mine planner. Three dimensional maps can be made of overburden depth, coal thickness and bulking factor, and mining and post mining topography simulated. Each aspect can be viewed, changed and updated continually. Spoil levelling and soil replacement can be optimised by such modelling.
073205 Prevention of cracking and water leakage in the concrete inner fining of frozen shafts. Short communication Yu Gongchun lnt J Min Geoi Engng I,'4, N3, Oct 1986, P247-251 Coal deposits on both banks of the Huai River in the Anhui Province of the People's Republic of China are overlain by 200 to 400m of saturated Quaternary alluvium which contains clay, marl and uncemented sand, making shaft sinking impractical unless assisted by some form of ground freezing. Shaft sinking in frozen ground in China utilizes a double lining design/construction method. Because of the high temperature gradient in the concrete lining when this is formed by casting against the frozen ground, the consequent thermal stresses combined with stresses resulting from the shrinkage of the cast concrete often cause fissures or cracks in the shaft lining. Two examples are described to illustrate how cracking has been eliminated in several frozen shafts by developing this innovative double lining method.
8732O6 Ground freezing for soft ground shaft sinking Shuster, J A Proc of the 1985 Rapid Excavation and Tunneling Conference, New York, 16-20 June 1985 II2, P1046-1059. Publ New York: AIME, 1985 Case histories are reported for several soft ground shafts, ranging from 6ft to 40ft in diameter and 50ft to 230ft in overburden depth, for which ground freezing was employed to provide temporary ground support and groundwater control during shaft sinking through the overburden. Cases reported emphasized dealing with difficult site and ground conditions such as working within existing buildings, through very soft, running and bouldery soils, in the presence of substantial lateral groundwater flows, and into salt dome deposits requiring special considerations. Construction procedures, schedule, and relative costs are discussed for each case. Auth.
Surface Structures 873207 Planning criteria for open pit mines under special consideration of slope stability and controlled blasting Weise, H Proc 2nd Symposium in Ranchi, German Open Pit Mining, 21-22 No~ 1985 Paper B1, 13P. Essen: Giuckauf, 1985 Slope stability considerations are important in planning of open cast mines. The main factors to be taken into account are groundwater, geologic structures and rock mechanical properties, slope height, length and angle, and required slope stand time. Combinations of slope stability,angle and dimensions determine the extractable reserves. The use of controlled blasting to shatter consolidated material and permit the use of bucket wheel excavators is briefly considered.
Base courses and pavements 873209 Permeability of geotextile-included railroad bed under repeated load Saxena, S K; Hsu, T S Geotext Geomem V4, N1, 1986, P31-51 Geotextiles are used in railroad beds to separate ballast from subgrade fines and to stop migration of the soil fines. The change in permeability of a simulated railroad bed with time and with number of load applications has been studied in the laboratory. Permeability decreased, due to clogging of the soil fines in and around the textile, with increasing time and with the increase in the number of cycle of repeated load. Reasons for the pumping action are discussed. A sequence of processes for the clogging of the railbed is proposed. 873210 Geotextile reinforced unpaved logging roads: the effect of anchorage Douglas, R A; Kelly, M A Geotext Geomem I,'4, N2, 1986, P93-106 The use of geotextiles to reinforce unpaved roads is becoming common. The assumption that increasing the modulus of the geotextile will increase the stiffness of the road has been examined in large scale model tests. The results, in conjunction with previous work, indicate that geotextile modulus has no significant effect on overall road stiffness, for quasi-static strip load tests, whether the geotextiles are fully anchored or completely free at the edges. 873211 Mount Pleasant Airport, Falkland Islands: design Skeene, G; Brice, G J lnst Civ Engng Proc, Part 1 II82, Feb 1987, P77-96 The significant aspects of the design of the civil engineering works for Mount Pleasant Airport, Falkland Islands, are described. The works include a 2590m main runway, taxiways, aprons, and over 150 buildings with all the associated infrastructure required, on a green field site in a remote and arduous location. 873212 Stability of gravel sub-bases Earland, M G; Pike, D C Transport and Road Research Laboratory Research report N64, 1986, 17P A series of trafficking tests was part of a study of the stability of unbound granular sub-bases. Results of these tests were correlated with shear strengths measured in a 300ram shear box machine, modified to test wet aggregates with plastic fines. Estimates of the precision of this test were made. Many gravel sub-bases performed as well as crushed reck type 1 sub-bases.
© 1987 Pergamon Journals Ltd. Reproduction not permitted