History of the development

Шарль Огюстен де КУЛОН

Charles-Augustin de Coulomb, 14 июня 1736— 23 августа 1806)

В 1773 году в Парижской академии наук им был зачитан, а впоследствии издан мемуар «Coulomb C.A. Essai sur une application des règles des maximis et minimis à quelques problems de statique relatives à ľarhitecture. Mem acad. pres. diver’s savants. vol. 7. Paris, 1776.( Эссе о применении правил максимумов и минимумов к некоторым проблемам связанным со статическими задачами архитектуры – мой перевод (240 лет -Кулону 37 лет)- (1971 -40 лет).

Грунт - это конгломерат твердых частиц разных размеров, формы и происхождения, в том числе органического, а также жидкостей и газов, В расчетах грунт рассматривается в виде сплошной среды, бесконечно малая часть, которой идентична целому.

Определение в Интернете.

Грунт – это любые горные породы, почвы, осадки, техногенные (антропогенные) образования, представляющие собой многокомпонентные, динамичные системы, являющиеся компонентами геологической среды и объектом инженерно-хозяйственной деятельности человека.

Английский.

Soil – this is a three phase conglomerate of particles of different sizes, shape and genesis, including organic as well as pore water and gas. In calculations the soil is regarded as a continuum, an infinitely small part of which is identical to the whole.

Mohr–Coulomb theory

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Mohr–Coulomb theory is a mathematical model (see yield surface) describing the response of brittle materials such as concrete, or rubble piles, to shear stress as well as normal stress. Most of the classical engineering materials somehow follow this rule in at least a portion of their shear failure envelope. Generally the theory applies to materials for which the compressive strength far exceeds the tensile strength.^[1]

In Geotechnical Engineering it is used to define shear strength of soils and rocks at different effective stresses.

In structural engineering it is used to determine failure load as well as the angle of fracture of a displacement fracture in concrete and similar materials. Coulomb'sfriction hypothesis is used to determine the combination of shear and normal stress that will cause a fracture of the material. Mohr's circle is used to determine which principal stresses that will produce this combination of shear and normal stress, and the angle of the plane in which this will occur. According to the principle of normality the stress introduced at failure will be perpendicular to the line describing the fracture condition.

It can be shown that a material failing according to Coulomb's friction hypothesis will show the displacement introduced at failure forming an angle to the line of fracture equal to the angle of friction. This makes the strength of the material determinable by comparing the external mechanical work introduced by the displacement and the external load with the internal mechanical work introduced by the strain and stress at the line of failure. By conservation of energy the sum of these must be zero and this will make it possible to calculate the failure load of the construction.

A common improvement of this model is to combine Coulomb's friction hypothesis with Rankine's principal stress hypothesis to describe a separation fracture.

History of the development

The Mohr–Coulomb theory is named in honour of Charles-Augustin de Coulomb and Christian Otto Mohr. Coulomb's contribution was a 1776 essay entitled "Essai sur une application des règles des maximis et minimis à quelques problèmes de statique relatifs à l'architecture" .^[2] Mohr developed a generalised form of the theory around the end of the 19th century.^[3] As the generalised form affected the interpretation of the criterion, but not the substance of it, some texts continue to refer to the criterion as simply the 'Coulomb criterion'.^[4]