Constant Pressure and Constant Volume Direct Shear Tests on Reinforced Sand

Effects of Reinforcement type and Loading History on the Deformation of Reinforced Sand in Plane Strain Compression

“…This fact indicates that the geogrid shape has signiˆcant eŠects on the strength and deformation characteristics of geogrid-reinforced sand. Qiu et al (2000) showed that the tensile reinforcing eŠects increase with an increase in the covering ratio (CR) and the degree of dispersion of reinforcing members under otherwise the same conditions. The CRs of the PET and PVA geogrids are similar, 22.2z and 25z, while the degree of dispersion was larger with the PET geogrid than the PVA geogrid.…”

Displacement Analyses for a Natural Slope Considering Post-Peak Strength of Soils

“…where t: normalized strength deterioration from peak to residual states Y: normalized post-peak shear stress X: normalized post-peak shear displacement parameter ∆ f : shear displacement at peak stress states Values of t for various soils derived based on the reported stress-displacement curves [18,19,[23][24][25][26][27][28] are summarized in Figure 4a. The values of t vary over a range of 0.1 to 0.5 for various soils.…”

“…For a specific soil, values of t can be expressed as a linear function of confining stress, σ n . Among the test results shown in Figure 4a, those for two direct shear tests conducted in regions of central Taiwan, reported by Wu [18] and Hsu [19] (see Based on the results of medium-or large-scale direct shear tests on various granular materials [19,[23][24][25][26][27][28], the shear displacement at residual states (Δr) can be expressed as a function of the shear displacement at the peak strength state (Δf) as:…”

Viscous Property of Toyoura Sand Over a Wide Range of Shear Deformation Rate and its Model Simulation

“…This DS apparatus is characterised by the following features; 1) a feedback control of the vertical normal stress by adjusting the air-pressures applied to two air cylinders so that the upper shear box is always accurately kept level (e.g., Mikasa, 1960;Jewell and Wroth, 1987;Shibuya et al, 1997) while the total normal load is always kept constant; 2) travelling of the lower shear box on a pair of very lowfriction rails; 3) accurate evaluation of the shear and vertical stresses acting in the central shear zone by careful design of the apparatus, in particular by the use of a pair of load cells to evaluate any friction acting on the bottom of the lower shear box, which is essential to ensure that rate-dependent responses in the measured shear stress are due fully to material viscous properties; and 4) direct measurements of shear displacements between the upper and lower boxes with a laser displacement transducer. The importance of these features to obtain reliable data of DS tests on granular materials was demonstrated by Qiu et al (2000) and Wu et al (2008). The details of the apparatus are given in Duttine et al (2008a, b).…”