Asperity (geotechnical engineering)

In geotechnical engineering and contact mechanics the term asperity is used to refer to individual features of unevenness (roughness) of the surface of a discontinuity, grain, or particle with heights in the range from approximately 0.1 mm to the order of metres. Below the asperity level, surface interactions are normally considered to be a material property, arising from mechanisms of adhesion and repulsion at the atomic scale (often accounted for by material friction, atomic friction or molecular friction).[1]

## Contents

* 1 Dilation
* 2 Contrast with asperity in materials science
* 3 See also
* 4 References
* 5 Further reading

## Dilation

An often used definition for asperities in geotechnical engineering:
Unevenness of a surface are asperities if these cause dilation if two blocks with in between a discontinuity with matching asperities on the two opposing surfaces (i.e. a fitting discontinuity) move relative to each other, under low stress levels that do not cause breaking of the asperities.

## Contrast with asperity in materials science

Materials science recognizes asperities ranging from the sub-visual (normally less than 0.1 mm) to the atomic scale.

## See also

* Discontinuity (Geotechnical engineering)
* Geotechnical engineering
* Rock mechanics
* Soil mechanics

## References

1. ↑ Patton, F.D. (25 Sep – 1 Oct 1966). "Multiple Modes of Shear Failure in Rock". in Rocha, M.. 1. Lisbon, Portugal: Laboratório Nacional de Engenharia Civil, Lisboa, Portugal. pp. 509–513.

## Further reading

* ASTM D5607 (2008). Standard Test Method for Performing Laboratory Direct Shear Strength Tests of Rock Specimens Under Constant Normal Force. ASTM International, West Conshohocken, PA, 2008. p. 450. doi:10.1520/D5607-08. http://www.astm.org/Standards/D5607.htm.

* Price, D.G. (2008). De Freitas, M.H.. ed. Engineering Geology: Principles and Practice. Springer. p. 450. ISBN 978-3-540-29249-4.

* Szymakowski, J.; Haberfield, C. (11–14 September 2001). "Preliminary results of direct shear testing of large scale, jointed, soft rock". Beijing, China: Swets & Zeitlinger, Lisse, Netherlands, Taylor & Francis. pp. 257–260. ISBN 90-265-1851-X.

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Asperity (geotechnical engineering). Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Asperity_(geotechnical_engineering)&oldid=2656569"