SAFETY OF BUILDING SYSTEMS. ECOLOGICAL PROBLEMS OF CONSTRUCTION PROJECTS. GEOECOLOGY

FORMATION OF DIFFERENT TYPES OF ENERGY CONTACTS IN SANDY SOILS IN THE FRAMEWORK OF THE PHYSICOCHEMICAL THEORY OF EFFECTIVE STRESSES

Vestnik MGSU 11/2012
  • Potapov Ivan Aleksandrovich - Scientific and Research Institute of Emergency Healthcare named after N.V. Sklifosovskiy engineer, Scientific and Research Institute of Emergency Healthcare named after N.V. Sklifosovskiy, ; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Potapov Aleksandr Dmitrievich - Moscow State University of Civil Engineering (MGSU) Doctor of Technical Sciences, Professor, Head, Department of Engineering Geology and Geoecology, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Shimenkova Anastasiya Anatolevna - Moscow State University of Civil Engineering (MGSU) engineer, Department of Engineering Geology and Geoecology, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 210 - 218

The authors examine the applicability of the physicochemical theory of effective stresses to
sandy soils. It is proven that the above theory may be furthered by the argument that all three
types of energy contacts, including coagulatory, transient and phase contacts, are present in sandy
soils. Coagulatory contact predominates over the other three types of contact. The authors provide
their findings in terms of morphological peculiarities attributable to genetic differences of quaternary
sands. The authors have completed an experimental research to identify the fixed water content in
sands and artificial mixtures that have a sand grain size, and they have also analyzed dimensions
of the per-unit surface of samples of natural sands and their fractions to identify correlation between
morphological peculiarities of sands and their maximal molecular water-absorbing capacity. The
authors have proven the presence of a correlation between the morphology of sand grains and their
number in the test sample exposed to the research undertaking, as it determines the number of
contacts between particles of sand.
The experimental data has proven that the principal provisions of the physicochemical theory
of effective stresses are applicable to sandy soils. Natural sands that have particles of different
shapes and surface nature demonstrate different types of contacts that prevent compliance of analytical
data with the results of experimental researches. Moreover, natural dimensions of coagulatory
contact areas of "sandy" systems substantially exceed those identified analytically. Areas of per-unit
surfaces of sands that contain particles with highly developed surfaces and clay films exceed those
of rounded particles the surfaces of which are smooth and polished as a result of their soft friction
in the water. This phenomenon boosts the thickness of adsorbed hydrated or solvated shells. As the
influence of physicochemical factors onto effective stresses in sands is not as prominent as in clays,
supplementary and more accurate experiments are to be held in respect of separate sand fractions
of monogene sands and in respect of samples of natural sands.

DOI: 10.22227/1997-0935.2012.11.210 - 218

References
  1. Trofimov V.T. Gruntovedenie [Soil Science]. Moscow, Nauka Publ., 2005, 1024 p.
  2. Pashkin E.M., Kagan A.A., Krivonogova N.F. Terminologicheskiy slovar’-spravochnik po inzhenernoy geologii [Dictionary of Terms and Reference Book of Engineering Geology]. Moscow, Universitet Publ., Knizhnyy dom publ., 2011, 950 p.
  3. Bely L.D., Doudler I.V., Mosiakov E.F., Potapov A.D., Julin A.N. Research Methods and Evaluation of Various Genesis Sand Grain Morphology Role in the Formation of Their Geological-Engineering Properties. Bulletin of IAEG, Krefeld, 1975, no. 11, vol. 1, pp. 27—31.
  4. Doudler I.V., Mosiakov E.F., Potapov A.D. Infl uence of Characteristic Moisture Content Values on Physical-chemical Properties of Sands of Various Genesis. Moscow, Moscow Institute of Civil Engineering, 1974, no. II 4, pp. 14—17.
  5. Platov N.A., Potapov A.D., Lebedeva M.D. Peschanye grunty [Sandy Soils]. Moscow, ASV Publ., 2010, 254 p.
  6. Potapov I.A., Shimenkova A.A., Potapov A.D. Zavisimost’ suffozionnoy ustoychivosti peschanykh gruntov razlichnogo genezisa ot tipa fi l’trata [Dependence of Suffosion Stability of Sandy Soils of Various Geneses on the Type of the Filtrate]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2012, no. 5, pp. 79—86.
  7. Anan’ev V.P., Potapov A.D. Inzhenernaya geologiya [Engineering Geology]. Moscow, Vyssh. shk. publ., 2008, 260 p.
  8. Osipov V.I. Fiziko-khimicheskaya teoriya effektivnykh napryazheniy v gruntakh [Physicochemical Theory of Effective Stresses in Soils]. Moscow, IFZ RAN Pub., 2012, 74 p.
  9. Potapov A.D. Morfologicheskoe izuchenie peskov razlichnogo genezisa v inzhenerno-geologicheskikh tselyakh [Morphological Research of Sands of Various Geneses for Engineering Geology Purposes]. Moscow, PNIIIS [Production, Scientific and Research Institute of Engineering Surveying in Construction], 1982.

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PARTICULAR ASPECTS OF APPLICABILITY OF PROVISIONS OF THE PHYSICAL AND CHEMICAL THEORY OF EFFECTIVE STRESSES TO SANDY SOILS

Vestnik MGSU 10/2012
  • Potapov Aleksandr Dmitrievich - Moscow State University of Civil Engineering (MGSU) Doctor of Technical Sciences, Professor, Head, Department of Engineering Geology and Geoecology, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Potapov Ivan Aleksandrovich - Scientific and Research Institute of Emergency Healthcare named after N.V. Sklifosovskiy engineer, Scientific and Research Institute of Emergency Healthcare named after N.V. Sklifosovskiy, .
  • Shimenkova Anastasiya Anatolevna - Moscow State University of Civil Engineering (MGSU) engineer, Department of Engineering Geology and Geoecology, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 229 - 239

The authors consider several aspects of applicability of the new approach to formation of effective stresses in soils in relation to sands, as it was set out in the theory developed by academician
V.I. Osipov. The analysis of several genetic types of quaternary sands, performed by the authors, makes it possible to use the number of contacts to identify the morphology of sand grains within the framework of the analysis of soils.
The authors demonstrate that the employment of the formulas developed by academician V.I. Osipov in the calculation of the number of contacts between particles in natural sandy soils is virtually impossible due to the fact that no natural sand particles can boast an ideal spherical shape. The number of contacts between the sand particles may increase due to the defects of their shape and the nature of the particle surface.
In this study, the shape and nature of the surface of sand grains represent those of the sands of various origins. The authors have employed a composite index of morphology that takes account of the shape and nature of the surface throughout the amount of sand under research. Similar calculations that take account of the morphology of grains were performed for selected fractions of sands to eliminate the influence of grain size on the packing of sands.
The analysis of provisions of the physical and chemical theory of effective stresses of soils and the study of multiple types of natural sands demonstrate that further research of formation and phases of coagulation contacts between particles of soil requires a detailed study of structural features of sands. These structural features include the grain size, homogeneity, the shape and nature of the surface of sand grains.
Both individual particles of sand and sandy soil are to be subjected to morphological assessments. The parameters to be assessed will include density and composition of sandy soils, as the soil porosity affects the formation of true contacts between particles of sand and determines their number. Mineral composition is an important factor affecting the shape and nature of the surface of sand grains. The research performed by the authors contemplates the study of the morphology of monogene, polymineral, oligomictic and polymictic sands. However quartz is the principal mineral in the structure of sand under research. Further research will cover other minerals to obtain more information about the formation of contacts between sand grains.

DOI: 10.22227/1997-0935.2012.10.229 - 239

References
  1. Osipov V.I. Fiziko-khimicheskaya teoriya effektivnykh napryazheniy v gruntakh [Physical and Chemical Theory of Effective Stresses of Soils]. Moscow, IGE RAN Publ., Moscow, 2012, 74 p.
  2. Potapov A.D. Morfologicheskoe izuchenie peskov v inzhenerno-geologicheskikh tselyakh [Morphological Study of Sands for the Purposes of Engineering Geology]. Moscow, PNIIIS Publ., 1981, 243 p.
  3. Friedman E. Packing Unit Squares in Squares. Elec. J. Combin. DS7, 1—24, Oct. 31, 2005. Available at: http://www.combinatorics.org/Surveys/ds7.html.
  4. Bely L.D, Doudler I.V., Mosiakov E.F., Potapov A.D., Julin A.N. Research Methods and Evaluation of Various Genesis Sand Grain Morphology Role in Formation of Their Geological-engineering Properties. Bulletin of IAEG, no. 11, 27-31, Krefeld, 1975.
  5. Doudler I.V., Mosiakov E.F., Potapov A.D. Influence of Characteristic Moisture Content Values on Physical-chemical Properties of Sands of Various Genesis. Moscow Institute of Civil Engineering, no. II, April 1974, pp. 14—17.
  6. Platov N.A., Potapov A.D., Lebedeva M.D. Peschanye grunty [Sandy Soils]. Moscow, ASV Publ., 2010. 254 p.
  7. Potapov I.A., Shimenkova A.A., Potapov A.D. Zavisimost’ suffozionnoy ustoychivosti peschanykh gruntov razlichnogo genezisa ot tipa fil’trata [Dependence of Suffosion Stability of Sandy Soils of Various Geneses on the Type of Filtrate]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2012, no. 5, pp. 79—86.

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