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886375 New limit equilibrium analysis of slope stability based on lower bound theorem
886370 Geotechnical centrifuge Bochum - model tests in high acceleration fields (In German) Jessberger, H L; Guttler, U Geotechnik Vll, N2. 1988. P85-97
886375 New limit equilibrium analysis of slope stability based on lower bound theorem Arai, K; Nakagawa, M Soils Found V28, Nl. March 1988, PI-15
The main features of the geotechnical centrifuge at Bochum are described. The basics of centrifuge modelling techniques and similitude for lg and ng tests are discussed. Initial experiments on slope stability and stresses around underground structures are reported.
A new numerical procedure for slope stability analysis, combining the slice method with the lower bound approach of the limit analysis method, is developed. The method gives an appropriate lower bound solution subject to the collapse mechanism represented by a potential slip surface. Firstly, a safety factor for a known slip surface is calculated. The stress field is discretised in a similar manner to the finite element displacement method. The procedure is applied to cases where the slip surface is already known, usually giving a higher safety factor than simplified Janbu method. Secondly, the assump tions used by slice methods are verified by using stress field determined by the proposed method. Finally, a critical noncircular slip surface, which minim&s the safety factor within lower bound conditions, is calculated.
886371 Continuum model for natural slopes in slow movement Vulliet, L; Hutter, K Geotechnique V38, N2, June 1988, P199-217 A two component mixture of an incompressible perfect liquid and a viscous isotropic soil in which stress may depend on porosity is used to model shallow landslides. Seepage forces are described by Darcy’s law. Explicit constitutive formulae are presented. Computations with simple flow configurations are used to demonstrate the significance of soil and slope parameters on the flow process and indicate the use of the model for predicting sliding. 886372 A posteriori analysis of the slopes of open pits in complex geological formations (Card coalIield - France) (In French) Han@ D; Arcamone, J; Laversanne, J Industrie Minerale V69, NlO,’Dee 1987, P385-389 Empirical methods to determine slope angles in open pit mines are inadequate for deep mines. A statistical approach using a relationship between dip and angle of repose is presented. This is useful when coupled with mechanical studies of the rock mass. The mechanical properties necessary may be determined in the laboratory if the failure mechanism is simple, otherwise an ‘a posterior? analysis of existing slopes permits estimation of cohesion and internal friction angle. Mercoirol and Grande-Baume strip mines are analysed, and the results used to obtain a range of possible values for cohesion and internal friction angle. 886373 Stability charts for wet conical deposits. Technical note Leshchinsky, D; Mullett, T L Int J Min Geol Engng L’S,N3, Ott 1987, P343-351 Mine waste materials are often dumped in heaps which approximate to symmetrical cones, and can undergo catastrophic rotational failure, especially after heavy rainfall. A three dimensional stability analysis based on the variational limit equilibrium method is presented. Possible failure mechanisms are considered, and results normalised and presented as non-dimensional design charts. 886374 Lit analysis slope stability with nonlinear yield condition. Short communication Drescher, A; Christopoulos, C Int J Num Anal Mel Geomech V12, NJ, May-June 1988, P341-345 A kinematic approach is presented to the limit analysis of an infinite, homogeneous, free-of-surcharge soil slope with a nonlinear Mohr-Coulomb yield criterion. It is an alternative approach to that of Zhang and Chen (1987) and solutions overestimate stability factors calculated by Zhang and Chen by only 1%. It is much simpler to apply, and its use is thus warranted in many cases. 0
886376 Probabilistic wedge failure analyses Rumpelt, T K; O’Connell-Jones, G Proc International Conference of the South African Institute of Mining and MetaZbrgy: Planning and Operution of Openpit and Strip Mines, Pretoria, 9-13 April I984 P13-22. Pub1 Johannesburg: South African Institute of Mining and Metallurgy, 1986
Probabilistic methods are used in rock engineering to account for statistical variations of geometry and strength properties of jointed rock. Two analyses of a 2 wedge plane failure are presented. The first is based on the Monte Carlo method. The second uses a new, simple technique, the point estimate method, which eliminates the necessity of the assumption of distribution types and their integrals, and requires less preparation and computing time. Relative merits of the analyses are compared. 886377 Geotechuical evaluation for open-pit planning Gash, P J S Proc International Conference of the South African Institute of Mining and Metalkugy: Plannhg and Operation of Openpit and Strip Mines, Pretoria, 9-13 April 1984 P23-36. Pub1 Johannesburg: South African Institute of Mining and Metallurgy, 1986
Geotechnical evaluation is used to get the best possible evaluation of ground conditions, in particular for slope design, taking into account strength, discontinuities and groundwater. Other factors such as diggability, blast design, and machinery type can be forecast. Examples illustrate mass failures of weak rock and discontinuity failures of competent ground. Site investigation and interpretation techniques, slope design guidelines, and effects of operation on stability are discussed. 886378 Strip slope angle selection from the probability of failure Call, R D; Caldwell, J A; Larson, N B Proc International Conference of the South African Institute of Mining and Metalkugy: Planning aad Operation of Openpit and Strip Mines, Pretoria, 9-13 April 1984 P47-53. Pub1 Johannesburg: South African Institute of Mining and Metallurgy. 1986
The example used to illustrate the procedure assumes a deposit of sub-horizontal layers of sands, silts, and clays as the overburden and interburden between coal or lignite seams. Geophysical logging and limited core logging are used to
1988 Pergamon Press plc. Reproduction
not permitted
886375 New limit equilibrium analysis of slope stability based on lower bound theorem Arai, K; Nakagawa, M Soils Found V28, Nl. March 1988, PI-15
The main features of the geotechnical centrifuge at Bochum are described. The basics of centrifuge modelling techniques and similitude for lg and ng tests are discussed. Initial experiments on slope stability and stresses around underground structures are reported.
A new numerical procedure for slope stability analysis, combining the slice method with the lower bound approach of the limit analysis method, is developed. The method gives an appropriate lower bound solution subject to the collapse mechanism represented by a potential slip surface. Firstly, a safety factor for a known slip surface is calculated. The stress field is discretised in a similar manner to the finite element displacement method. The procedure is applied to cases where the slip surface is already known, usually giving a higher safety factor than simplified Janbu method. Secondly, the assump tions used by slice methods are verified by using stress field determined by the proposed method. Finally, a critical noncircular slip surface, which minim&s the safety factor within lower bound conditions, is calculated.
886371 Continuum model for natural slopes in slow movement Vulliet, L; Hutter, K Geotechnique V38, N2, June 1988, P199-217 A two component mixture of an incompressible perfect liquid and a viscous isotropic soil in which stress may depend on porosity is used to model shallow landslides. Seepage forces are described by Darcy’s law. Explicit constitutive formulae are presented. Computations with simple flow configurations are used to demonstrate the significance of soil and slope parameters on the flow process and indicate the use of the model for predicting sliding. 886372 A posteriori analysis of the slopes of open pits in complex geological formations (Card coalIield - France) (In French) Han@ D; Arcamone, J; Laversanne, J Industrie Minerale V69, NlO,’Dee 1987, P385-389 Empirical methods to determine slope angles in open pit mines are inadequate for deep mines. A statistical approach using a relationship between dip and angle of repose is presented. This is useful when coupled with mechanical studies of the rock mass. The mechanical properties necessary may be determined in the laboratory if the failure mechanism is simple, otherwise an ‘a posterior? analysis of existing slopes permits estimation of cohesion and internal friction angle. Mercoirol and Grande-Baume strip mines are analysed, and the results used to obtain a range of possible values for cohesion and internal friction angle. 886373 Stability charts for wet conical deposits. Technical note Leshchinsky, D; Mullett, T L Int J Min Geol Engng L’S,N3, Ott 1987, P343-351 Mine waste materials are often dumped in heaps which approximate to symmetrical cones, and can undergo catastrophic rotational failure, especially after heavy rainfall. A three dimensional stability analysis based on the variational limit equilibrium method is presented. Possible failure mechanisms are considered, and results normalised and presented as non-dimensional design charts. 886374 Lit analysis slope stability with nonlinear yield condition. Short communication Drescher, A; Christopoulos, C Int J Num Anal Mel Geomech V12, NJ, May-June 1988, P341-345 A kinematic approach is presented to the limit analysis of an infinite, homogeneous, free-of-surcharge soil slope with a nonlinear Mohr-Coulomb yield criterion. It is an alternative approach to that of Zhang and Chen (1987) and solutions overestimate stability factors calculated by Zhang and Chen by only 1%. It is much simpler to apply, and its use is thus warranted in many cases. 0
886376 Probabilistic wedge failure analyses Rumpelt, T K; O’Connell-Jones, G Proc International Conference of the South African Institute of Mining and MetaZbrgy: Planning and Operution of Openpit and Strip Mines, Pretoria, 9-13 April I984 P13-22. Pub1 Johannesburg: South African Institute of Mining and Metallurgy, 1986
Probabilistic methods are used in rock engineering to account for statistical variations of geometry and strength properties of jointed rock. Two analyses of a 2 wedge plane failure are presented. The first is based on the Monte Carlo method. The second uses a new, simple technique, the point estimate method, which eliminates the necessity of the assumption of distribution types and their integrals, and requires less preparation and computing time. Relative merits of the analyses are compared. 886377 Geotechuical evaluation for open-pit planning Gash, P J S Proc International Conference of the South African Institute of Mining and Metalkugy: Plannhg and Operation of Openpit and Strip Mines, Pretoria, 9-13 April 1984 P23-36. Pub1 Johannesburg: South African Institute of Mining and Metallurgy, 1986
Geotechnical evaluation is used to get the best possible evaluation of ground conditions, in particular for slope design, taking into account strength, discontinuities and groundwater. Other factors such as diggability, blast design, and machinery type can be forecast. Examples illustrate mass failures of weak rock and discontinuity failures of competent ground. Site investigation and interpretation techniques, slope design guidelines, and effects of operation on stability are discussed. 886378 Strip slope angle selection from the probability of failure Call, R D; Caldwell, J A; Larson, N B Proc International Conference of the South African Institute of Mining and Metalkugy: Planning aad Operation of Openpit and Strip Mines, Pretoria, 9-13 April 1984 P47-53. Pub1 Johannesburg: South African Institute of Mining and Metallurgy. 1986
The example used to illustrate the procedure assumes a deposit of sub-horizontal layers of sands, silts, and clays as the overburden and interburden between coal or lignite seams. Geophysical logging and limited core logging are used to
1988 Pergamon Press plc. Reproduction
not permitted