name
Lyashenko Pavel Alekseyevich
Scholastic degree
•
Academic rank
associated professor
Honorary rank
—
Organization, job position
• Kuban State Agrarian University
кафедра оснований и фундаментов
профессор
Research interests
грунтоведение, механика грунтов, основания и фундаменты
Web site url
—
Current rating (overall rating of articles)
0
TOP5 co-authors
Articles count: 14
Сформировать список работ, опубликованных в Научном журнале КубГАУ
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THE CALCULATION OF THE SOIL MICRO-STRUCTURE CHARACTERISTICS IN CON-SOLIDATION TESTING OF SAMPLE
Description
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.
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THE STUDY OF PRECONSOLIDATION PRES-SURE OF LOAMY SOIL WITH THE CONSTANT RATE OF LOADING
Description
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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THE FILLING PILE SETTLEMENT PROCESS INVESTIGATION
Description
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
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RESEARCH THE FILLING PILE’S SETTLEMENT IN CLAY SOILS DURING REPEATED STATIC LOADING
Description
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
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CONTACT INTERACTION OF CLAYEY SOIL MICROSTRUCTURE ELEMENTS
Description
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
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LABORATORY MODELLING OF FILLING PILE
Description
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
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DEFORMATION MODEL OF SAND MICROSTRUCTURE
Description
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
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THE CALCULATION OF THE FOUNDATION SETTLEMENT OVER THE PLATE INVESTI-GATION DATA
Description
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
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HARDENING AND SOFTENING OF CLAY SOIL
Description
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
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PHYSICAL MODELING OF ODOMETRIC COMPRESSION OF SAND
Description
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
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