Name
Denisenko Viktor Viktorovich
Scholastic degree
•
Academic rank
—
Honorary rank
—
Organization, job position
Kuban State Technological University
Web site url
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Articles count: 7
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
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
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
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
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
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.
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