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Wave-induced failure of poroelastic seabed slopes: a boundary element study
255A
924385 Wave-indocnd failure of poroelastic seabed slopes: a boundary element study Raman-Nair, W; Sabin, G C W inst Ciu Engrs Proc 1/91, Pt2. Dec 1991, P771-794 The predictions of Biot's poroelasticity theory for the stability of a submarine slope under loading from ocean waves are examined. The wave forces on the slope and the induced pore pressures and effective stresses are calculated using the boundary element method. The extent of the failure zone is estimated on the basis of the Mohr Coulomb failure criterion. Results demonstrate that it is necessary to analyse induced stresses throughout an entire wave cycle in order to assess likelihood of failure. Stability is seen to be strongly influenced by initial stress condition.
924386 Static instability and liquefaction of loose fine sandy slopes Lade, P V J Geotech Engng Div ASCE VII8, NI. Jan 1992, P51-71 Soils which exhibit nonassociated flow may become unstable within the effective stress failure surface. Triaxial tests on fully and partially saturated samples under drained and undrained conditions were used to study regions of stable and unstable behaviour. Two cases are examined, a shallow marine slope and a steeper, nearly saturated slope typical of a tailings dam. Conventional stability analysis suggests these slopes are stable, but the procedure presented indicates potential for instability, which may be initiated by a small disturbance and become catastrophic.
924387 Failures and deformations of beds, foundations, and underground structures during industrial construction in Karaganda Filatov, A V Soil Mech Found Engng i/28, NI, Jan-Feb 1991. P6-11 Case histories of problems during construction are presented. At one site,investigation was not thorough enough to detect a stratum bearing water under pressure. Subsequent inflow into trenches caused side wall failures. Construction of a settling basin was similarly affected due to the presence of an undetected water bearing layer. Foundations of a coke plant chute failed because of poor compaction control of backfill. A large concrete lined shaft for a pumping plant came close to failure because of poor quality components and nonuniform placement of soils around the lining sections. Remedial measures are presented in all cases.
924388 Debris-flow phenomena in the Central Apennines of Italy Guzzetti, F; Cardinali, M Terra Nova I/3, N6, 1991, P619-627 Debris flows have played a significant role in shaping the landscape of the Monte Sibillini region. Three sections are found source, transport, and depositional areas. Source areas are landslide deposits, highly fractured rocks, scree or talus, or glacial deposits. The evolution of some major flows has been examined. An initial stage of gulley erosion or minor landsliding may progress to extensive mass movement, then a final stage dominated by fluvial transport. An examination of debris flow hazards of the area is made.
924389 Optimization calculations in the context of bock.analysis of slope failures Zhang, S; Chowdhury, R N Pro¢ 2nd International Symposium on Mine Planning and Equipment Selection,Calgary, 7-9 November 1990 P499-505. Publ Rotterdam: A A Balkema, 1990 Back analysis of a slope failure may be performed on the basis of observed failure surface or theoretical critical slip surface with minimum value of safety factor, the two rarely coinciding. In conventional back analysis, several parameters are assumed and the value of one unknown obtained. If both cohesion and friction angle are unknown, different combinations of these two parameters produce different locations of critical slip surface. The simplex optimisation method is proposed for easy evaluation of the pair of parameters giving best agreement between observed and theoretical critical failure surface. They may be taken as representative of overall shear strength of the medium. 924390 Simulation of settling and consolidation process for the assessment of tailings impoundments stability Ciccu, R; Manca, P P; Massacci, G; Pisanu, G Proc 2nd International Symposium on Mine Planning and Equipment Selection,Calgary, 7-9 November 1990 P523-530. Publ Rotterdam: A A Balkema, 1990 Tailings disposal presents many problems. The stability is dependent on many interrelated factors. A suite of computer programs to assist in the stability analysis is described. SECTION2D analyses vertical consolidation and settlement, taking account of tailings properties, initial and changing geometry of the impoundment, and boundary conditions. Profiles of effective stresses along vertical alignments are produced. SPLINE interpolates data from SECTION2D to map effective stress values which are input data for STABILITY which evaluates safety factors and critical slip surfaces. 924391 Geomembranes, geotextiles and slope stability Hausmann, M R; Sadlier, M A; Beckingsale, C Proc 6th Australia-New Zealand Conference on Geomechanics, Christchurch, 3-7 February 1992 P77-82. Publ New Zealand." New Zealand Geomechanics Society, 1992 Heap leach pads are generally constructed on gentle slopes on a geotextile/geomembrane liner. Friction between liner components and heap components is an important parameter for design. Cracking at the top of the heap and wrinkling of the liner at the base often indicate developing heap instability. A failure analysis is presented for the case of a small heap which failed because of sliding of the geomembrane over the textiles. Recommendations are made for suitable construction methods and materials and for remedial measures to be taken if precursors of instability are seen. 924392 Stabilisation of rock cuttings on the Florence to Worcester section of National Route NI, South Africa Hendry, R W; Crowther, J; Holmes, R Proc ISRM International Symposium on Static and Dynamic Considerations in Rock Engineering, Swaziland, 10-12 September 1990 P133-138. Publ Rotterdam: A A Balkema, 1990 Four major cuts were excavated in the Nordouw Formation quartzitic sandstones of the Table Mountain group. Expected slope instabilities were confirmed by occurrence of minor slides by simple planar and toppling failure in two of the cuts. Bolts were used to prevent block toppling, and anchors
© 1992 Pergamon Press Ltd. Reproduction not permitted
924385 Wave-indocnd failure of poroelastic seabed slopes: a boundary element study Raman-Nair, W; Sabin, G C W inst Ciu Engrs Proc 1/91, Pt2. Dec 1991, P771-794 The predictions of Biot's poroelasticity theory for the stability of a submarine slope under loading from ocean waves are examined. The wave forces on the slope and the induced pore pressures and effective stresses are calculated using the boundary element method. The extent of the failure zone is estimated on the basis of the Mohr Coulomb failure criterion. Results demonstrate that it is necessary to analyse induced stresses throughout an entire wave cycle in order to assess likelihood of failure. Stability is seen to be strongly influenced by initial stress condition.
924386 Static instability and liquefaction of loose fine sandy slopes Lade, P V J Geotech Engng Div ASCE VII8, NI. Jan 1992, P51-71 Soils which exhibit nonassociated flow may become unstable within the effective stress failure surface. Triaxial tests on fully and partially saturated samples under drained and undrained conditions were used to study regions of stable and unstable behaviour. Two cases are examined, a shallow marine slope and a steeper, nearly saturated slope typical of a tailings dam. Conventional stability analysis suggests these slopes are stable, but the procedure presented indicates potential for instability, which may be initiated by a small disturbance and become catastrophic.
924387 Failures and deformations of beds, foundations, and underground structures during industrial construction in Karaganda Filatov, A V Soil Mech Found Engng i/28, NI, Jan-Feb 1991. P6-11 Case histories of problems during construction are presented. At one site,investigation was not thorough enough to detect a stratum bearing water under pressure. Subsequent inflow into trenches caused side wall failures. Construction of a settling basin was similarly affected due to the presence of an undetected water bearing layer. Foundations of a coke plant chute failed because of poor compaction control of backfill. A large concrete lined shaft for a pumping plant came close to failure because of poor quality components and nonuniform placement of soils around the lining sections. Remedial measures are presented in all cases.
924388 Debris-flow phenomena in the Central Apennines of Italy Guzzetti, F; Cardinali, M Terra Nova I/3, N6, 1991, P619-627 Debris flows have played a significant role in shaping the landscape of the Monte Sibillini region. Three sections are found source, transport, and depositional areas. Source areas are landslide deposits, highly fractured rocks, scree or talus, or glacial deposits. The evolution of some major flows has been examined. An initial stage of gulley erosion or minor landsliding may progress to extensive mass movement, then a final stage dominated by fluvial transport. An examination of debris flow hazards of the area is made.
924389 Optimization calculations in the context of bock.analysis of slope failures Zhang, S; Chowdhury, R N Pro¢ 2nd International Symposium on Mine Planning and Equipment Selection,Calgary, 7-9 November 1990 P499-505. Publ Rotterdam: A A Balkema, 1990 Back analysis of a slope failure may be performed on the basis of observed failure surface or theoretical critical slip surface with minimum value of safety factor, the two rarely coinciding. In conventional back analysis, several parameters are assumed and the value of one unknown obtained. If both cohesion and friction angle are unknown, different combinations of these two parameters produce different locations of critical slip surface. The simplex optimisation method is proposed for easy evaluation of the pair of parameters giving best agreement between observed and theoretical critical failure surface. They may be taken as representative of overall shear strength of the medium. 924390 Simulation of settling and consolidation process for the assessment of tailings impoundments stability Ciccu, R; Manca, P P; Massacci, G; Pisanu, G Proc 2nd International Symposium on Mine Planning and Equipment Selection,Calgary, 7-9 November 1990 P523-530. Publ Rotterdam: A A Balkema, 1990 Tailings disposal presents many problems. The stability is dependent on many interrelated factors. A suite of computer programs to assist in the stability analysis is described. SECTION2D analyses vertical consolidation and settlement, taking account of tailings properties, initial and changing geometry of the impoundment, and boundary conditions. Profiles of effective stresses along vertical alignments are produced. SPLINE interpolates data from SECTION2D to map effective stress values which are input data for STABILITY which evaluates safety factors and critical slip surfaces. 924391 Geomembranes, geotextiles and slope stability Hausmann, M R; Sadlier, M A; Beckingsale, C Proc 6th Australia-New Zealand Conference on Geomechanics, Christchurch, 3-7 February 1992 P77-82. Publ New Zealand." New Zealand Geomechanics Society, 1992 Heap leach pads are generally constructed on gentle slopes on a geotextile/geomembrane liner. Friction between liner components and heap components is an important parameter for design. Cracking at the top of the heap and wrinkling of the liner at the base often indicate developing heap instability. A failure analysis is presented for the case of a small heap which failed because of sliding of the geomembrane over the textiles. Recommendations are made for suitable construction methods and materials and for remedial measures to be taken if precursors of instability are seen. 924392 Stabilisation of rock cuttings on the Florence to Worcester section of National Route NI, South Africa Hendry, R W; Crowther, J; Holmes, R Proc ISRM International Symposium on Static and Dynamic Considerations in Rock Engineering, Swaziland, 10-12 September 1990 P133-138. Publ Rotterdam: A A Balkema, 1990 Four major cuts were excavated in the Nordouw Formation quartzitic sandstones of the Table Mountain group. Expected slope instabilities were confirmed by occurrence of minor slides by simple planar and toppling failure in two of the cuts. Bolts were used to prevent block toppling, and anchors
© 1992 Pergamon Press Ltd. Reproduction not permitted