On the Measurement of Critical State Parameters of Dense Granular Soils

1993 ◽  
Vol 16 (1) ◽  
pp. 27 ◽  
Author(s):  
HJ Pincus ◽  
J Chu ◽  
S-CR Lo
Keyword(s):  
Critical State ◽  
Granular Soils ◽  
Critical State Parameters

scholarly journals The critical state line of nonplastic tailings

2020 ◽  
Vol 57 (10) ◽  
pp. 1508-1517
Author(s):  
L.A. Torres-Cruz ◽  
J.C. Santamarina
Keyword(s):  
Grain Size ◽  
Critical State ◽  
Engineering Practice ◽  
Friction Coefficients ◽  
Granular Packing ◽  
Scale Characteristics ◽  
Tailing Dams ◽  
Critical State Parameters

The probability of failure of tailing dams and associated risks demand improvements in engineering practice. The critical state line provides a robust framework for the characterization of mine tailings. New experimental data for nonplastic platinum tailings and a large database for tailings and nonplastic soils (grain size between 2 and 500 μm) show that the critical state parameters for nonplastic tailings follow the same trends as nonplastic soils as a function of particle-scale characteristics and extreme void ratios. Critical state lines determined for extreme tailings gradations underestimate the range of critical state parameters that may be encountered in a tailings dam; in fact, mixtures with intermediate fines content exhibit the densest granular packing at critical state. The minimum void ratio emin captures the underlying role of particle shape and grain size distribution on granular packing and emerges as a valuable index property to inform sampling strategies for the assessment of spatial variability. Mineralogy does not significantly affect the intercept Γ100, but it does affect the slope λ. The friction coefficients M of tailings are similar to those of other nonplastic soils; while mineralogy does not have a significant effect on friction, more angular grains lead to higher friction coefficients.

Effect of vibration on the critical state of dry granular soils

2015 ◽  
Vol 17 (6) ◽  
pp. 687-702 ◽  
Author(s):  
Karen A. Taslagyan ◽  
Dave H. Chan ◽  
Norbert R. Morgenstern
Keyword(s):  
Critical State ◽  
Granular Soils

Physical and mechanical properties of a compacted silty sand with low bentonite fraction

1998 ◽  
Vol 35 (6) ◽  
pp. 909-925 ◽  
Author(s):  
Filippo Santucci de Magistris ◽  
Francesco Silvestri ◽  
Filippo Vinale
Keyword(s):  
Mechanical Properties ◽  
Critical State ◽  
Physical And Mechanical Properties ◽  
Silty Sand ◽  
Granular Soils ◽  
Fine Grained ◽  
Optimum Water Content ◽  
Geotechnical Structures ◽  
Slurry Consolidation ◽  
Good Agreement

Compacted granular soils with small additions of bentonite have been used to build geotechnical structures such as impervious liners and cores of zoned earth dams. This paper presents a laboratory study showing how physical and mechanical characteristics of a silty sand are modified by a low percentage of bentonite. The effects of the addition of bentonite on the silty sand are reflected by an increase in the plasticity index, a reduction in maximum modified Proctor density, and a decrease in hydraulic conductivity. The most significant consequences on the mechanical properties are an increase of compressibility and secondary consolidation coefficients, and a reduction in shear strength. Different mixtures were either dynamically compacted at the optimum water content (compacted samples) or prepared after slurry consolidation from the minimum density (remoulded samples). Although the compacted and remoulded specimens show different isotropic compression lines, their critical-state lines in the v:p':q space are identical, where v is specific volume, p' is average effective stress, and q is deviator stress. Comparisons of the mechanical parameters with the existing literature database show that the compression coefficients of the remoulded mixtures are comparable to those of normally consolidated clayey soils of similar plasticity; nevertheless, those of the compacted mixtures are considerably lower. Also, the slopes of their critical-state lines in the q:p' plane are in good agreement with those predicted by empirical correlations for fine-grained soils.Key words: bentonite, silty sand, compaction, physical properties, compressibility, critical state.

Isotropic–kinematic hardening model for coarse granular soils capturing particle breakage and cyclic loading under triaxial stress space

2016 ◽  
Vol 53 (4) ◽  
pp. 646-658 ◽  
Author(s):  
Qingsheng Chen ◽  
Buddhima Indraratna ◽  
John P. Carter ◽  
Sanjay Nimbalkar
Keyword(s):  
Cyclic Loading ◽  
Critical State ◽  
Kinematic Hardening ◽  
Plasticity Theory ◽  
Particle Breakage ◽  
Granular Soils ◽  
Stress Space ◽  
Bounding Surface ◽  
Bounding Surface Plasticity ◽  
Surface Plasticity

In this paper, a simple but comprehensive cyclic stress–strain model that incorporates particle breakage for granular soils including ballast and rockfill has been proposed on the basis of bounding surface plasticity theory within a critical state framework. Particle breakage and its effects are captured by a critical state line that is translated in voids ratio–stress space according to the dissipated energy (plastic work), through a hyperbolic function. A comprehensive equation related to particle breakage is proposed for the stress–dilatancy relationship to capture the complex dilatancy of granular soils. By extending Masing’s rule to bounding surface plasticity theory and introducing a generalized homological centre, a combined isotropic–kinematic hardening rule and a mapping rule have been established to simulate more realistically the response of gravelly soils under cyclic loading. The applicability and accuracy of this model are demonstrated by comparing its predictions with experimental results for different types of granular soils, including rockfill, under both monotonic and cyclic loading conditions. This study shows that the model can capture the characteristic features of coarse granular soils under complex loading paths.

Critical State Parameters

1978 ◽  
Vol 104 (4) ◽  
pp. 497-501
Author(s):  
Yudhbir ◽  
V. Kuganathan ◽  
Surendra K. Mathur
Keyword(s):  
Critical State ◽  
Critical State Parameters
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