Particle breakage occurs when the stresses imposed on soil particles exceed their strength. To quantify the amount of breakage, many particle breakage factors have been proposed. Correlations of particle breakage parameters with standard soil parameters such as effective mean normal stress at failure and void ratio at failure do not provide a fully unified correlation with many different types of tests. However, particle breakage factors appear to correlate very well with the total energy input into the test specimen, thus providing a single unifying parameter for all types of soil tests. Therefore, the amount of particle crushing may be predicted if the stresses and strains in the soil can be estimated, such as in a finite-element analysis. The principal significant use of these particle breakage factors may be related to permeability estimates when there are changes in gradation due to particle breakage. A new particle breakage factor, B 10 , is proposed that will allow easy permeability computations wh...

Significance of particle crushing in granular materials

Porous Materials Water in Porous Materials Flow in Porous Materials Unsaturated Flows Unsaturated Flow in Building Physics Composite Materials Evaporation and Drying Topics in Water Transport Appendices Symbols Used Properties of Water Minerals, Salts and Solutions Other Liquids Other Data

Water Transport in Brick, Stone and Concrete

New data from observations of asteroid mutural perturbation events, observations of asteroid satellites, and spacecraft encounters have revolutionized our understanding of asteroid bulk density.

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Asteroid Density, Porosity, and Structure

Microscopic particle crushing of sand subjected to high pressure one-dimensional compression

Traditional railway foundations or substructures have become increasingly overloaded in recent years due to the introduction of faster and heavier trains. A lack of substructure re-engineering has resulted in maintenance cycles becoming more frequent and increasingly expensive. Two significant problems arising from increasing axle loads are differential track settlement and ballast degradation. One potential method of enhancing the substructure is by manipulating the level of ballast confinement. To investigate this possibility, a series of high frequency cyclic triaxial tests have been conducted to examine the effects of confining pressure and

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Effect of confining pressure on the degradation of ballast under cyclic loading

A one-dimensional testing apparatus was developed to test soils to axial stresses up to 850 MPa. The apparatus was instrumented with strain gauges such that lateral soil stresses, and therefore K0 , could be inferred from measured circumferential strains. Three different initial densities of quartz, Cambria, and gypsum sands were tested and it was found that the effect of initial density was eliminated at high stress magnitudes. This stress magnitude was higher for mineralogically harder grains than for softer grains. The inferred values of K0 for the mineralogically harder Cambria sand was found to be constant at high pressures, but slightly below that indicated by Jaky's equation. However, the softer gypsum sand indicated increasing values of K0 as the stress magnitude increased. This apparently was caused by inelastic, viscous flow during shearing.

Paul A. Bopp

Papers

Significance of particle crushing in granular materials

One-Dimensional Compression of Sands at High Pressures

Relative density effects on drained sand behavior at high pressures

Influence of time effects on instability of granular materials

Instability of dilating sand