Lateral Earth Support Structures
A retaining wall is a structure that holds back earth. Retaining walls stabilize soil and rock from downslope movement or erosion and provide support for vertical or near-vertical grade changes. Cofferdams and bulkheads, structures to hold back water, are sometimes also considered retaining walls.
The primary geotechnical concern in design and installation of retaining walls is that the retained material is attempting to move forward and downslope due to gravity. This creates soil pressure behind the wall, which can be analysed based on the angle of internal friction (φ) and the cohesive strength (c) of the material and the amount of allowable movement of the wall. This pressure is smallest at the top and increases toward the bottom in a manner similar to hydraulic pressure, and tends to push the wall forward and overturn it. Groundwater behind the wall that is not dissipated by a drainage system causes an additional horizontal hydraulic pressure on the wall.
Read more about this topic: Geotechnical Engineering
Famous quotes containing the words earth, support and/or structures:
“Sport is the bloom and glow of a perfect health. The great will not condescend to take anything seriously; all must be as gay as the song of a canary, though it were the building of cities, or the eradication of old and foolish churches and nations, which have cumbered the earth long thousands of years.”
—Ralph Waldo Emerson (1803–1882)
“American families, however, without exception, experience a double message in our society, one that claims a commitment to families and stresses the importance of raising bright, stable, productive citizens, yet remains so bound by an ideal of “rugged individualism” that parents receive little support in their task from the public or private sectors.”
—Bernice Weissbourd (20th century)
“It is clear that all verbal structures with meaning are verbal imitations of that elusive psychological and physiological process known as thought, a process stumbling through emotional entanglements, sudden irrational convictions, involuntary gleams of insight, rationalized prejudices, and blocks of panic and inertia, finally to reach a completely incommunicable intuition.”
—Northrop Frye (b. 1912)