Lateral earth pressure

Earth pressure is a term of geotechnical engineering and is particularly important for the establishment ( foundation ) of buildings meaningful. Regarding the size of the earth pressure, there are two extreme cases:

• The active earth pressure is the minimum pressure, the predetermined properties, a floor, a building ( for example a supporting wall or a gabion wall ) can exert a predetermined geometry. This minimum is achieved only if the building can yield to the pressure within certain limits. Otherwise, the loads are higher, one speaks of the increased active earth pressure.
• The passive earth pressure is the largest earth pressure with which a soil can support a building wall. This maximum occurs only when movement of the structure in the centimeter and decimeter range in general.
• Between these two values ​​is the earth pressure at rest.

Active earth pressure and passive earth pressure depend inter alia on the following parameters: Density, consistency and internal friction angle of the soil, distance from the surface and slope of the terrain, vertical loads (eg buildings and vehicles), inclination of the building wall and the coefficient of friction between the floor and wall.

Under otherwise identical conditions, the passive earth pressure is much larger than the active. The components of the earth pressure in horizontal and vertical directions are referred to as horizontal or vertical earth pressure. Of importance is also the earth pressure at rest, which applies, for rigid and non-displaceable buildings that are filled from both sides.

History

In France, first Vauban addressed by rational methods with the Erddrucklehre for his Fortress retaining walls ( after Jean Kerisel ), his memorandum to (profile général de Vauban pour les murs de soutènement ), he sent his engineers in 1667, but is not preserved.

1691 by Pierre Bullet comes the first attempt to earth pressure theory. He assumed at the time that the horizontal force due to earth pressure on a wall is as large as the weight of a frictionless bearings Erdkeiles that is reached at an angle of 45 ° behind the wall and presses against the wall. The same theory was of Bernard de Bélidor in his book of 1729 La science of Ingénieurs.

Pierre couplet of Tortreaux developed 1729/1730 a rigid-body theory of the vault and certain earth pressure on vault and walls. His theory was to the earth pressure theory of Coulomb.

Coulomb Established 1776 on an improved earth pressure theory. In it, the Coulomb yield criterion is used to calculate the earth pressure on structures.

In the 19th century, various graphical techniques were developed (for example, Karl Culmann, Christian Otto Mohr ). In England Rankine earth pressure theory developed in 1857. Further improvements made ​​in Germany to Heinrich Müller -Breslau whose Erddrucktabellen were used much from the beginning of the 20th century. In France, Albert and Jean Caquot Kerisel gave in the 1940s out Erddrucktafeln, which were based on non-planar sliding surfaces and were also applicable to passive earth pressure.