A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation,...A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation, their comparison and their decrease with depth is discussed. The depth where a permeability of 3 to 5×10-7m/sec can be retained (the limit of a reasonable grouting under a high dam) may be twofold if the geological history of the formation could not contain a compressional tectonic process. This depth may reach 100m in some cases. The differences in the mean values of permeability among the various litho-types are minor, while the presence of siltstones, always present although with varied participation, dramatically controls the global permeability.展开更多
The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the typ...The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the type A and type B systems were carried out to investigate the pull-out capacities and the slope stability reinforcement efficiency in soil and rock slopes.The results of the pull-out tests show the mobilized shear force and load transfer characteristics with respect to soil depth.The load-displacement relationship was examined for both type A and type B systems.Slope stability analyses were carried out to study the relationships between soil and nail reinforcement and bending stiffness as well as combined axial tension and shear forces.Factors of safety were calculated in relation to the number of nails and their outside diameters.Both soil and rock slopes were included in this evaluation.展开更多
文摘A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation, their comparison and their decrease with depth is discussed. The depth where a permeability of 3 to 5×10-7m/sec can be retained (the limit of a reasonable grouting under a high dam) may be twofold if the geological history of the formation could not contain a compressional tectonic process. This depth may reach 100m in some cases. The differences in the mean values of permeability among the various litho-types are minor, while the presence of siltstones, always present although with varied participation, dramatically controls the global permeability.
文摘The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the type A and type B systems were carried out to investigate the pull-out capacities and the slope stability reinforcement efficiency in soil and rock slopes.The results of the pull-out tests show the mobilized shear force and load transfer characteristics with respect to soil depth.The load-displacement relationship was examined for both type A and type B systems.Slope stability analyses were carried out to study the relationships between soil and nail reinforcement and bending stiffness as well as combined axial tension and shear forces.Factors of safety were calculated in relation to the number of nails and their outside diameters.Both soil and rock slopes were included in this evaluation.
