Soil structure

Soil structure (from lat. Structura - structure, location) - in engineering geology , a set of features that reflect the size, shape, nature of the surface, the quantitative ratio of the structural elements of the soil (individual grains, particles, aggregates, cement, glass) and the nature of their relationship with a friend.

Under the structure of the soil understand the relative position of different in size and shape of the mineral particles and aggregates and the nature of the relationships between them, due to the entire history of the soil. ^[one]

In Russian soil science, ideas about the structure of soil have developed thanks to the works of M.M. Filatov (1936), I.V. Popov (1941, 1949), V. A. Priklonsky (1955), E. M. Sergeeva (1946, 1956, 1958 ), I.M. Gorkova (1965), A.K. Larionova (1966), V.I. Osipova (1983), V.N.Sokolova (1988), etc. The structure and texture of the soil are the most important elements of its structure ( see soil structure).

Depending on the scale of the structural features of the soil, its structure, structure and texture can be studied visually (in outcrops and rock samples) or using technical methods. means. In these cases, along with the general terms “structure”, “structure” and “texture”, the same terms are used with the prefixes “macro” (for signs that are visible to the naked eye), or “micro-” (for signs that are not visible to the naked eye) . The structure of any soil (as well as the structure of the crystal) is characterized by periodicity, i.e. constant repeatability within the soil distribution region of a certain elementary group of structural elements (or a representative volume of the soil structure). Soil is only a multiple repetition of this elementary group throughout its distribution area. The idea of ​​periodicity of soil structures has been emphasized by many researchers. However, the macrostructure of the soil is not a simple summation of elementary groups or microstructures, because it also manifests system-forming features - heterogeneities of various orders, etc.

Soil structures are divided according to various criteria, but there is no unified classification of soil structures of different types. In engineering-geological study of rocks, along with the isolation of microstructures according to petrographic characteristics, they are subdivided according to the nature of structural bonds (chemical, physical, physico-chemical, etc.), because they determine the strength and deformability of soils .

According to V.I. Osipov (1983), the following types of microstructures are distinguished: crystallization; cementation or condensation-crystallization; coagulation; transient; mixed (including: coagulation-cementation and coagulation-crystallization); and incoherent (loose) microstructures. In addition, there are structures and textures of unfrozen and frozen soils, in the formation of which ice plays a significant role. In the latter case, structures and textures are called cryogenic.

Literature:

• Soil Science / Ed. V.T. Trofimova, 6th ed. - M.: Publishing House of Moscow State University, 2005.1024 s .;
• Basic concepts of engineering geology and environmental geology: 280 basic terms. / Ed. V.T. Trofimova. - M., JSC Geomarketing, 2012, 320 p.
• Grigoryeva I.Yu. Microstructure of loess rocks. - M., MAIK "Science / Interperiodica", 2001;
• Larionov A.K. Engineering-geological study of the structure of loose sedimentary rocks. - M., 1966;
• Osipov V.I., Sokolov V.N., Rumyantseva N.A. The microstructure of clay rocks. / Under the editorship of E.M. Sergeev - M., "Nedra", 1989;
• Polovinkina Yu.I. Structures and textures of igneous and metamorphic rocks. Part 1. - M., 1966.