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Search for critical slip surfaces based on finite element method
SURFACE STRUCl-URES:SLOPES slices in traditional slice methods. All slope stability analyses based on the limit equilibrium of slices can be interpreted in the context of their implicitly assumed collapse mechanisms. The static assumptions made are equivalent to assuming an arbitrary strength of the soil on interfaces between slices. A convenient way to include pore pressure effects is also presented and implemented in the analysis of both translational and rotational slope collapse. (from Author) 963308
Plane failure analysis of rock slopes S. Sharma, T. K. Raghuvanshi & R. Anbalagan, Geofechnical & Geological Engineering, 13(2), 1995, pp 105-l 11. Hoek and Bray (1981) gave an analytical approach for plane failure analysis for rock slopes that is limited to those slopes in which the upper slope surface is horizontal and the tension crack is vertical. An analysis is presented here which can take these factors into account. It is found that varying the angle of the upper slope from 0” to 30” causes a significant reduction in the factor of safety. Varying the tension crack from vertical to 70” only has an effect when the upper slope angle is less than 20”. (Authors) 963309
Search for critical slip surfaces based on finite element method Jin-Zhang Zou, D. J. Williams & Wen-Lin Kiong, Canadian Geotechnical Journal, 32(2), 1995, pp 233-246. Finite element methods are used to determine local shear strength mobilization ratios within a slope and to indicate the probable location of the critical slip surface. To locate the critical slip surface and hence determine the minimum factor of safety, an improved dynamic programming method (IDPM) is employed. Results obtained using the FEMIDPM, for a homogeneous slope and for a test embankment on soft Bangkok clay, have been compared with those observed and obtained using the traditional finite element method and the generalized limit equilibrium wedge method. (from Author) 963310 Stability of infinite slopes J. A. M. Teunissen & S. E. J. Spierenburg, Geotechnique, 45(2), 1995, pp 321-323. In a research programme on the stability of overtopping dykes in the Netherlands, attention is focused on the inner slope. Within the inner slope a parallel flow develops which affects the geomechanical stability. One of the aims of this research is to derive simple design rules, in particular for the inner slope gradient for this loading condition. The stability condition just within the soil layer has been proved more critical than the stability condition considering the shear stress and normal stress ratio at the failure surface only. For infmite slopes the simple shear condition is generally a more critical condition for failure than interface behaviour for materials with identical strength parameters. (from Authors) 963311 Engineering a landslide D. Brown & J. Wolosick, Civil Engineering - AXE, 65(7), 1995, pp 72-73. A slope failure in northwest Alabama has been stabilized using a system of grouted ‘INSERT’ piles to provide load transfer across the failure surface of the slide. This system, referred to as a ‘Type A’ wall, includes small diameter grout piles reinforced with a high strength steel pipe as well as permanent earth anchors. A program of instrumentation was installed to verify the performance of this system and measure the axial, shear, and bending forces in the key elements. This paper describes the INSERT wall repair of the slide as well as the plan and installation of the instrumentation. (from Author)
137A
963312 Simplified design methods for pipelines subject to transverse and longitudinal soil movements B. B. Rajani, P. K. Robertson & N. R. Morgenstem, Canadian Geotechnical Journal, 32(2), 1995, pp 309-323. As landslide movements develop, pipelines can undergo transverse and longitudinal displacements and the resistance offered by the surrounding soil steadily increases depending on the soil characteristics. This resistance reaches an ultimate as the soil reaches failure and develops plastic strains. Two simple analytical solutions have been developed based on this concept: one for transverse movements and another for longitudinal movements. Nondimensional relationships have been developed and are presented in the form of charts which permit hand calculations and rapid verification of structural design of the pipeline and, thus, assess the integrity of existing pipelines located in areas with ground instability. (from Authors)
963313 A generalized procedure for the optimum design of nailed soil slopes N. Sabhahit, P. K. Basudhar & M. R. Madhav, International Journal for Numerical & Analytical Metho& in Geomechanits, 19(6), 1995, pp 437-452. A new method is proposed for the optimum design of nailed soil slopes. A rigorous method of stability analysis, namely the Janbu’s method, is modified in the limit equilibrium formation, considering the effect of reinforcement. The effect of the number and relative locations of the reinforcements on the amount of reinforcement required, is studied. The lengths of reinforcement required to raise the factor of safety to various desired values and the corresponding optimum designs are presented. The acceptability of the critical surface is verified, by ensuring that the shear and normal stresses are positive along the critical surface. (from Authors)
963314 Seepage-induced slope failures on sandbars in Grand - Canyon R. Gobin & M. Budhu, Journal of Geozechnical Engineering ASCE, 121(8), 1995, pp 601-609. The effect of fluctuating discharge from Glen Canyon Dam on downstream sandbars is of significant concern. In this contribution, the observations of seepage-related erosion caused by fluctuations in dam discharge are presented. It is shown that the limiting stable seepage slope becomes a predefined failure plane. Sand deposited above this stable seepage slope will eventually fail along the predefined plane from gravitational forces, high pore-water pressure and seepage forces. (Authors)
963315 Embankment failures at Vernon, British Columbia C. B. Crawford, R. J. Fannin & C. B. Kern, Canadzizn Geotechnical Journal, 32(2), 1995, pp 271-284. A section of Highway 97, west of Vernon, is located over a soft-to-firm, compressible, silty clay subsoil. The performance of two test embankments was observed for 2 years before construction was begun on the highway grade between them. When the highway fill reached a maximum thickness of about 10 m a failure occurred. The design was then changed to include berms in either side, but a second failure occurred when the grade was rebuilt. Observations of settlements, pore pressures, and lateral movements in the subsoil describe the performance of the embankment during construction and reveal the importance of strain softening as a factor in the failures. Comparisons with a variety of similar failures in Canada, Scandinavia, and southeast Asia provide some guidance for future construction over similar materials. (from Authors)
Plane failure analysis of rock slopes S. Sharma, T. K. Raghuvanshi & R. Anbalagan, Geofechnical & Geological Engineering, 13(2), 1995, pp 105-l 11. Hoek and Bray (1981) gave an analytical approach for plane failure analysis for rock slopes that is limited to those slopes in which the upper slope surface is horizontal and the tension crack is vertical. An analysis is presented here which can take these factors into account. It is found that varying the angle of the upper slope from 0” to 30” causes a significant reduction in the factor of safety. Varying the tension crack from vertical to 70” only has an effect when the upper slope angle is less than 20”. (Authors) 963309
Search for critical slip surfaces based on finite element method Jin-Zhang Zou, D. J. Williams & Wen-Lin Kiong, Canadian Geotechnical Journal, 32(2), 1995, pp 233-246. Finite element methods are used to determine local shear strength mobilization ratios within a slope and to indicate the probable location of the critical slip surface. To locate the critical slip surface and hence determine the minimum factor of safety, an improved dynamic programming method (IDPM) is employed. Results obtained using the FEMIDPM, for a homogeneous slope and for a test embankment on soft Bangkok clay, have been compared with those observed and obtained using the traditional finite element method and the generalized limit equilibrium wedge method. (from Author) 963310 Stability of infinite slopes J. A. M. Teunissen & S. E. J. Spierenburg, Geotechnique, 45(2), 1995, pp 321-323. In a research programme on the stability of overtopping dykes in the Netherlands, attention is focused on the inner slope. Within the inner slope a parallel flow develops which affects the geomechanical stability. One of the aims of this research is to derive simple design rules, in particular for the inner slope gradient for this loading condition. The stability condition just within the soil layer has been proved more critical than the stability condition considering the shear stress and normal stress ratio at the failure surface only. For infmite slopes the simple shear condition is generally a more critical condition for failure than interface behaviour for materials with identical strength parameters. (from Authors) 963311 Engineering a landslide D. Brown & J. Wolosick, Civil Engineering - AXE, 65(7), 1995, pp 72-73. A slope failure in northwest Alabama has been stabilized using a system of grouted ‘INSERT’ piles to provide load transfer across the failure surface of the slide. This system, referred to as a ‘Type A’ wall, includes small diameter grout piles reinforced with a high strength steel pipe as well as permanent earth anchors. A program of instrumentation was installed to verify the performance of this system and measure the axial, shear, and bending forces in the key elements. This paper describes the INSERT wall repair of the slide as well as the plan and installation of the instrumentation. (from Author)
137A
963312 Simplified design methods for pipelines subject to transverse and longitudinal soil movements B. B. Rajani, P. K. Robertson & N. R. Morgenstem, Canadian Geotechnical Journal, 32(2), 1995, pp 309-323. As landslide movements develop, pipelines can undergo transverse and longitudinal displacements and the resistance offered by the surrounding soil steadily increases depending on the soil characteristics. This resistance reaches an ultimate as the soil reaches failure and develops plastic strains. Two simple analytical solutions have been developed based on this concept: one for transverse movements and another for longitudinal movements. Nondimensional relationships have been developed and are presented in the form of charts which permit hand calculations and rapid verification of structural design of the pipeline and, thus, assess the integrity of existing pipelines located in areas with ground instability. (from Authors)
963313 A generalized procedure for the optimum design of nailed soil slopes N. Sabhahit, P. K. Basudhar & M. R. Madhav, International Journal for Numerical & Analytical Metho& in Geomechanits, 19(6), 1995, pp 437-452. A new method is proposed for the optimum design of nailed soil slopes. A rigorous method of stability analysis, namely the Janbu’s method, is modified in the limit equilibrium formation, considering the effect of reinforcement. The effect of the number and relative locations of the reinforcements on the amount of reinforcement required, is studied. The lengths of reinforcement required to raise the factor of safety to various desired values and the corresponding optimum designs are presented. The acceptability of the critical surface is verified, by ensuring that the shear and normal stresses are positive along the critical surface. (from Authors)
963314 Seepage-induced slope failures on sandbars in Grand - Canyon R. Gobin & M. Budhu, Journal of Geozechnical Engineering ASCE, 121(8), 1995, pp 601-609. The effect of fluctuating discharge from Glen Canyon Dam on downstream sandbars is of significant concern. In this contribution, the observations of seepage-related erosion caused by fluctuations in dam discharge are presented. It is shown that the limiting stable seepage slope becomes a predefined failure plane. Sand deposited above this stable seepage slope will eventually fail along the predefined plane from gravitational forces, high pore-water pressure and seepage forces. (Authors)
963315 Embankment failures at Vernon, British Columbia C. B. Crawford, R. J. Fannin & C. B. Kern, Canadzizn Geotechnical Journal, 32(2), 1995, pp 271-284. A section of Highway 97, west of Vernon, is located over a soft-to-firm, compressible, silty clay subsoil. The performance of two test embankments was observed for 2 years before construction was begun on the highway grade between them. When the highway fill reached a maximum thickness of about 10 m a failure occurred. The design was then changed to include berms in either side, but a second failure occurred when the grade was rebuilt. Observations of settlements, pore pressures, and lateral movements in the subsoil describe the performance of the embankment during construction and reveal the importance of strain softening as a factor in the failures. Comparisons with a variety of similar failures in Canada, Scandinavia, and southeast Asia provide some guidance for future construction over similar materials. (from Authors)