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Deep seated rockslide initiated by ore mining
385A from the relatively small but more destructible underground workings. The time scales of these ground movements are compared. 926354 Deep seated rockslide initiated by ore mining Rybar, J, Kostak, B; Uher, M Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August 1990 V4, P2681-2686. Publ Rotterdam: A A Balkema, 1990 A deep seated rockslide in the massif above a mine in Western Bohemia, where tin deposits beneath the old open pit are worked, led to appearance of a tension crack close to pit structures in 1988. Investigations led to the conclusion that sliding is on an almost planar surface and results from collapse of the underground workings. It cannot be controlled by limiting output. Sudden movement is considered unlikely and the movement will continue to be monitored, with an alarm limit of 1.5x current rate specified.
926358 Use of field data in design of rock slopes Matheson, G D Rock Mechanics as a Maltidisciplinary Science, Proc 32nd US Symposium, Norman, 10-12 July 1991 P1083-1093. Publ Rotterdam: A ,4 Balkema, 1991 Natural instability and that resulting from excavation must be minimised to achieve stable rock slopes. The design must take account of geotechnical conditions of the rock mass, and damage during construction must be kept as low as possible, The collection of data on discontinuity characteristics is discussed. Traditional methods of presentation and evaluation of failure potential are first illustrated, then computer-assisted methods described. The program ROCKSTAB is presented which allows both traditional stereographic and sensitivity histogram methods to be applied to field discontinuity data.
Earth retaining structures See also: 926297
926355 Block theory and stability analysis of a slope subject to lateral spread. The example of 'Chiusi della Verna' mountain Garzonio, C A Proc International Conference on Mechanics o f Jointed and Faulted Rock, Vienna, 18-20 April 1990 P913-918. Publ Rotterdam: A A Balkema, 1990 In large areas of the Apennines, fractured limestone rocks overlie ductile tectonised clay complexes. Lateral spread movement results in landslides of various forms. The effects of movement of the viscous underlayer on the stability of the limestone mass have been examined. Block removal, sliding, and toppling failures have been observed. Instability conditions of some rock walls have been examined using limit equilibrium methods and block theory.
926356 Toppling and deep-seated landslides in natural slopes Pritchard, M A; Savigny, K W; Evans, S G Proc International Conference on Mechanics o f Jointed and Faulted Rock, Vienna, 18-20 April 1990 P937-943. Publ Rotterdam. A A Balkema, 1990 The distinct element method of analysis was used to study the relation between toppling failure and deep-seated landslides. The computer program UDEC, which has been verified as suitable for block and flexural toppling,was applied. Different combinations of rock mass strength parameters that lead to toppling deformations and failures were identified. 926357 Stability evaluation of high mountainous slopes by a method of percolation theory Kostak, B; Kudrna, Z Rock Mechanics as a Multith'sciplinary Science: Proc 32nd US Symposium, Norman, 10-12 July 1991 P811-820. Publ Rotterdam." A A Balkema, 1991 Slopes of the Krusne Hory mountains rising above the North Bohemia coal basin of Czechoslovakia are stable at the present, but large scale extraction may alter the stress state in the massif. Geological investigations have indicated the possibility of slope deformations, including a deep seated failure beneath the toe. Because of the scale of the slopes, survey is not possible, and stability analysis must be by stochastic methods. The application of percolation theory to risk evaluation is presented as one solution.
926359 Performance of an anchored sheet pile wall on the CN Rail line, Boston Bar, British Columbia Gaffran, P; Sego, D C; Peterson, A E Can Geotech J V29, NI, Feb 1992, P31-38 A 6m high multilevel-anchored sheet pile wall containing crushed argillaceous bedrock backfill was constructed to widen the railbed in the Fraser River Valley. Load distributions along the tensioned anchors and strain and lateral displacements of the wall were monitored. Earth pressure distributions inferred from field measurements were reasonably predicted using the Terzaghi and Peck recommendations, and were in turn used to calculate displacement profiles by modelling the wall as a beam. The results obtained justify the use of a simple technique to predict the displacement of the anchored wall.
926360 Field measurement of anchor forces, ground temperatures, and pore-water pressures behind a retaining structure in northwestern Ontario Eigenbrod, K D; Burak, J P Can Geotech J V29, NI, Feb 1992, Pl12-116 Results are presented from monitoring an anchored sheet pile retaining wall over a 2 year period. Anchor forces increased from an initial average of 5kN up to about 50kN during the winter periods, but dropped back to initial values during summer periods. These forces were largely independent of pore pressure variations behind the wall. Rapid drawdown resulted in almost instantaneous anchor load increase, equivalent to the unloading effect in front of the wall, but pore pressures behind the wall were largely unaffected. Freezing pressures were low, as the large heat capacity of the groundwater body prevented freezing below the water table. 926361 Analysis of braced excavations with coupled finite element formulations Einno, R J; Harahap, I S, Sabatini, P J Comput Geotech V12. N2, 1991, P91-114 Finite element methods are well suited to modelling of sequential processes. Results are presented of a parametric study of a deep braced excavation through soft to medium stiff saturated clay. Relative effects of commonly made assumptions on the deformation behaviour of braced excavations are evaluated.
',i') 1992 Pergamon Press Ltd. Reproduction not permitted
926358 Use of field data in design of rock slopes Matheson, G D Rock Mechanics as a Maltidisciplinary Science, Proc 32nd US Symposium, Norman, 10-12 July 1991 P1083-1093. Publ Rotterdam: A ,4 Balkema, 1991 Natural instability and that resulting from excavation must be minimised to achieve stable rock slopes. The design must take account of geotechnical conditions of the rock mass, and damage during construction must be kept as low as possible, The collection of data on discontinuity characteristics is discussed. Traditional methods of presentation and evaluation of failure potential are first illustrated, then computer-assisted methods described. The program ROCKSTAB is presented which allows both traditional stereographic and sensitivity histogram methods to be applied to field discontinuity data.
Earth retaining structures See also: 926297
926355 Block theory and stability analysis of a slope subject to lateral spread. The example of 'Chiusi della Verna' mountain Garzonio, C A Proc International Conference on Mechanics o f Jointed and Faulted Rock, Vienna, 18-20 April 1990 P913-918. Publ Rotterdam: A A Balkema, 1990 In large areas of the Apennines, fractured limestone rocks overlie ductile tectonised clay complexes. Lateral spread movement results in landslides of various forms. The effects of movement of the viscous underlayer on the stability of the limestone mass have been examined. Block removal, sliding, and toppling failures have been observed. Instability conditions of some rock walls have been examined using limit equilibrium methods and block theory.
926356 Toppling and deep-seated landslides in natural slopes Pritchard, M A; Savigny, K W; Evans, S G Proc International Conference on Mechanics o f Jointed and Faulted Rock, Vienna, 18-20 April 1990 P937-943. Publ Rotterdam. A A Balkema, 1990 The distinct element method of analysis was used to study the relation between toppling failure and deep-seated landslides. The computer program UDEC, which has been verified as suitable for block and flexural toppling,was applied. Different combinations of rock mass strength parameters that lead to toppling deformations and failures were identified. 926357 Stability evaluation of high mountainous slopes by a method of percolation theory Kostak, B; Kudrna, Z Rock Mechanics as a Multith'sciplinary Science: Proc 32nd US Symposium, Norman, 10-12 July 1991 P811-820. Publ Rotterdam." A A Balkema, 1991 Slopes of the Krusne Hory mountains rising above the North Bohemia coal basin of Czechoslovakia are stable at the present, but large scale extraction may alter the stress state in the massif. Geological investigations have indicated the possibility of slope deformations, including a deep seated failure beneath the toe. Because of the scale of the slopes, survey is not possible, and stability analysis must be by stochastic methods. The application of percolation theory to risk evaluation is presented as one solution.
926359 Performance of an anchored sheet pile wall on the CN Rail line, Boston Bar, British Columbia Gaffran, P; Sego, D C; Peterson, A E Can Geotech J V29, NI, Feb 1992, P31-38 A 6m high multilevel-anchored sheet pile wall containing crushed argillaceous bedrock backfill was constructed to widen the railbed in the Fraser River Valley. Load distributions along the tensioned anchors and strain and lateral displacements of the wall were monitored. Earth pressure distributions inferred from field measurements were reasonably predicted using the Terzaghi and Peck recommendations, and were in turn used to calculate displacement profiles by modelling the wall as a beam. The results obtained justify the use of a simple technique to predict the displacement of the anchored wall.
926360 Field measurement of anchor forces, ground temperatures, and pore-water pressures behind a retaining structure in northwestern Ontario Eigenbrod, K D; Burak, J P Can Geotech J V29, NI, Feb 1992, Pl12-116 Results are presented from monitoring an anchored sheet pile retaining wall over a 2 year period. Anchor forces increased from an initial average of 5kN up to about 50kN during the winter periods, but dropped back to initial values during summer periods. These forces were largely independent of pore pressure variations behind the wall. Rapid drawdown resulted in almost instantaneous anchor load increase, equivalent to the unloading effect in front of the wall, but pore pressures behind the wall were largely unaffected. Freezing pressures were low, as the large heat capacity of the groundwater body prevented freezing below the water table. 926361 Analysis of braced excavations with coupled finite element formulations Einno, R J; Harahap, I S, Sabatini, P J Comput Geotech V12. N2, 1991, P91-114 Finite element methods are well suited to modelling of sequential processes. Results are presented of a parametric study of a deep braced excavation through soft to medium stiff saturated clay. Relative effects of commonly made assumptions on the deformation behaviour of braced excavations are evaluated.
',i') 1992 Pergamon Press Ltd. Reproduction not permitted