dilatancy

It is well known that rocks near an earthquake-prone zone will exhibit dilatancy.

This phenomenon of cracks opening and closing in response to changing stress conditions is called dilatancy.

The peak strength of the soil may be greater, however, due to the interlocking (dilatancy) contribution.

The scientific term for this is "Reynold's Dilatancy".

The expansion of the particle matrix due to shearing was called dilatancy by Osborne Reynolds.

Movement of the overlying glacier may cause the bed to undergo dilatancy; the resulting shape change reorganises blocks.

If it had originally been in a dense state, then it typically gains volume, a characteristic known as Reynolds' dilatancy.

This effect, as well as other possible precursors, has been attributed to dilatancy, where rock stressed to near its breaking point expands (dilates) slightly.

In addition to the friction and interlocking (dilatancy) components of strength, the structure and fabric also play a significant role in the soil behavior.

Reynolds, O., "On the dilatancy of media composed of rigid particles in contact, with experimental illustrations," Phil.

Reynolds' dilatancy is the observed tendency of a compacted granular material to dilate (expand in volume) as it is sheared.

Reynolds, O., "Experiments showing dilatancy, a property of granular material, possibly connected with gravitation," Proc.

Dilatancy in a colloid, or its ability to order in the presence of shear forces is dependent on the ratio of interparticle forces.

The curvature (nonlinearity) of the failure envelope occurs because the dilatancy of closely packed soil particles depends on confining pressure.

Not recognizing the significance of dilatancy, Coulomb proposed that the shear strength of soil may be expressed as a combination of adhesion and friction components:

These include segregation, stratification, jamming and unjamming, fragility, loss of kinetic energy, frictional shearing, compaction and Reynolds' dilatancy.

From the triaxial test data, it is possible to extract fundamental material parameters about the sample, including its angle of shearing resistance, apparent cohesion, and dilatancy angle.

One, called dilatancy theory, he said, is similar to what happens when people go out on a beach and step in wet sand and the sand gets dry around their feet.

Reynolds' dilatancy is a common feature of the soils and sands studied by geotechnical engineers, and is a part of the broader topic of soil mechanics.

Soil mechanics, which describes the behavior of soil, is also complicated because soils exhibit nonlinear (stress-dependent) strength, stiffness, and dilatancy (volume change associated with application of shear stress).

The British popular-science programme Brainiac: Science Abuse demonstrated dilatancy dramatically by filling a swimming pool with this mixture and having presenter Jon Tickle walk across it.

But aside from Haicheng, which was based on anecdotal reports, dilatancy has never been observed before an earthquake, Dr. Jordan said, and it was later shown that the idea would not work.

Both the uplift and the changes in seismic velocities were predicted by the then current dilatancy theory, although Whitcomb emphasized his "hypothesis test" was based solely on the seismic velocities, and that he regarded that theory unproven.