Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
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Name

Lyashenko Pavel Alekseyevich

Scholastic degree


Academic rank

associated professor

Honorary rank

Organization, job position

Kuban State Agrarian University
   

Web site url

Email

lyseich1@yandex.ru


Articles count: 14

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364 kb

CONTACT INTERACTION OF CLAYEY SOIL MICROSTRUCTURE ELEMENTS

abstract 0781204025 issue 78 pp. 282 – 309 30.04.2012 ru 1451
The conception of mobile contact has been suggested for the clay particles and their microaggregates. The contact has been presented as the plane particle between microaggregates, which can turn over the point of fixing to one of them and interacts with both of them. There has been shown that contact particle describes elastic and plastic-viscous resistance to transference of adjacent microaggregates
405 kb

DEFORMATION MODEL OF SAND MICROSTRUCTURE

abstract 1181604051 issue 118 pp. 853 – 877 29.04.2016 ru 724
The deformation model of sand soil that takes into account the formation of clusters of particles, and method of measuring its characteristics is suggested. The physical basis of the method is the effect of the stepwise increasing of the sand probe at the odometer pressure by the constant rate of loading and the continuous measuring of deformation. The analysis of settlement and its rate has been allowed to determine the microstructural characteristics of the two-order deformation model of sand. According to the proposed model, with compression of the probe in odometer compaction of the sand takes place due to local strains on the sliding surfaces. The sliding surfaces allocate clusters of sand, and the separated layers of clusters are registered by device in the form of steps of deformation. Layer formation of clusters is initiated by the rigid stamps through the largest mineral grains. Cluster layers create the asymmetric microstructure of the sand probe, its compaction is non uniform but also anisotropic. At the initial interval value of the pressure, the formation of primary clusters occurs, and once they cover the entire probe volume, the compaction of the sand is by crushing them on the secondary smaller cluster sizes. The change of mechanism of the compaction is manifested in the sharp decrease of the settlement rate. The compaction process continues while a larger increment of pressure at each step. The deformation model allows compute the pressure value at which the compaction of the sand reaches the theoretical limit
376 kb

HARDENING AND SOFTENING OF CLAY SOIL

abstract 1201606103 issue 120 pp. 1541 – 1557 30.06.2016 ru 435
Hardening of clay soil manifests in the form of increase of the resistance of sample to shear deformation. The shear tests of normally compacted and overcompacted soils give values of peak strength at small strains and long-term strength at high. A shear test with constant strain rate of deformation (CRD) with continuous recording of resistance encounters uneven resistance change and the cyclical rate of change of resistance (RCR). The identification of cycles of the SIS allowed us to divide the deformation in each cycle for elastic and inelastic, corresponding to the ascending and descending branches of cycle. On an interval of the total resistance, the increases of the increment of inelastic strain are positive up to some critical value of the total deformation of the sample at which their sum reaches a maximum. This maximum is adopted as a measure of hardening. With further shearing of the sample, inelastic increments are negative, and their sum is monotonously decreases and reaches negative values for the total destruction of the sample. This value is taken as the softening. A symptom of total failure of the sample is the decline of absolute values of inelastic increments of resistance to zero. In general, the trend of the increments of inelastic and elastic increments of the resistance of the sample indicates the development of the destruction of the soil sample on the sliding surfaces and, in particular, yielding of the total surface. The sum of elastic increments of the resistance monotonically increases throughout the shear
1091 kb

LABORATORY MODELLING OF FILLING PILE

abstract 0661102023 issue 66 pp. 245 – 260 28.02.2011 ru 1882
The grounds of modeling of filling pile static resistance have been offered so as the results of its realization at the laboratory models. The laboratory testing data are compared with the data of field testing of natural piles. The experimental and the model calculated values of bearing capacity shows the correlation coef-ficient 0,692. The laboratory tests confirm the exis-tence of the local maximum of the settlement “accele-ration”. The point of maximum proposed separates two stages of bearing capacity increment process: the stage of lateral surface mainly resistance and the stage of pile bottom mainly resistance
1128 kb

PHYSICAL MODELING OF ODOMETRIC COMPRESSION OF SAND

abstract 1221608047 issue 122 pp. 681 – 700 31.10.2016 ru 462
The odometric compression of sand with constant rate of loading (CRL) or constant rate of deformation (CRD) and continuous registration of the corresponding reaction allows to identify the effect of stepwise changes of deformation (at the CRL) and the power reaction (at the CRD). Physical modeling of compression on the sandy model showed the same effect. The physical model was made of fine sand with marks, mimicking large inclusions. Compression of the soil at the CRD was uneven, stepwise, and the strain rate of the upper boundary of the sandy model changed cyclically. Maximum amplitudes of cycles passed through a maximum. Inside of the sand model, the uneven strain resulted in the mutual displacement of the adjacent parts located at the same depth. The growth of external pressure, the marks showed an increase or decrease in displacement and even move opposite to the direction of movement (settlement) the upper boundary of the model ‒ "floating" of marks. Marks, at different depths, got at the same time different movements, including mutually contradictory. The mark settlements sudden growth when the sufficiently large pressure. These increments in settlements remained until the end of loading decreasing with depth. They were a confirmation of the hypothesis about the total destruction of the soil sample at a pressure of "structural strength". The hypothesis of the "floating" reason based on the obvious assumption that the marks are moved together with the surrounding sand. The explanation of the effect of "floating" is supported by the fact that the value of "floating" the more, the greater the depth
1290 kb

RESEARCH THE FILLING PILE’S SETTLEMENT IN CLAY SOILS DURING REPEATED STATIC LOADING

abstract 1201606104 issue 120 pp. 1558 – 1575 30.06.2016 ru 376
The object of the study is bored piles and their joint work with clay soils. The analysis of the field of static tests of bored piles, arranged by continuous flight auger technology (CFA), was carried out by repeated loading. Curve of settlement and the rate of its development from the applied force was obtained. Linear relationship reducing the amount of settlement in the second cycle from residual displacements after unloading pile on the first cycle was found. There was a relationship increment of settlements in the second cycle from the involvement of the bottom end in the work
284 kb

THE CALCULATION OF THE FOUNDATION SETTLEMENT OVER THE PLATE INVESTI-GATION DATA

abstract 0470903001 issue 47 pp. 1 – 19 31.03.2009 ru 3912
The basis of foundation settlement modeling over the plate testing has been offered. The similarity criteria were formulated so as the formulas for settling incre-ments calculation versus to setting pressure increments on the base of foundation. New principle of admissible pressure on the base of foundation has been suggested
201 kb

THE CALCULATION OF THE SOIL MICRO-STRUCTURE CHARACTERISTICS IN CON-SOLIDATION TESTING OF SAMPLE

abstract 0450901003 issue 45 pp. 30 – 46 30.01.2009 ru 3019
The method of determination of clay soil microstruc-ture characteristics over the results on consolidation testing with constant rate loading has been described. The characteristics of 12 different soils are presented.
931 kb

THE FILLING PILE SETTLEMENT PROCESS INVESTIGATION

abstract 0901306009 issue 90 pp. 115 – 134 30.06.2013 ru 1839
The filling piles and their joint work with soil are the objects of research. The joint working of filling piles and soil has been researched with the constant rate of loading (CRL) and the continuous measuring of deformations of physical model. The experiment was realized at the physical model of filling pile in soil with the apparatus AKP-6NM. The hypothesis of mechanical working of near-pile soil was proposed as the result of the experiment
1303 kb

THE STUDY OF PRECONSOLIDATION PRES-SURE OF LOAMY SOIL WITH THE CONSTANT RATE OF LOADING

abstract 0841210047 issue 84 pp. 620 – 634 28.12.2012 ru 2174
The preconsolidation pressure of natural loamy soils was researched with the method of constant rate of loading (CRL) and the continuous measuring of de-formations at the apparatus AKP-6NM. The results of the rate of deformation analysis have been offered. The method of the preconsolidation pressure and the crumple pressure values has been suggested based on the rate of deformation analysis
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