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Rate effect on the shear resistance of sandy clay in direct shear tests

100%

Dolzyk-Szypcio K., Chmielewska I.

Acta Scientiarum Polonorum. Architectura

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2017

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tom 16

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nr 4

The influence of shear velocity on shear resistance of a sandy clay at different moisture content and stress level during direct shear tests is investigated. The stress ratio and dilatancy relationship gives a new possibility of interpreting the results of direct shear tests results. The mobilized shear resistance is a function of pore pressure in a shear band and possibility of this pressure dissipation into the upper and lower part of the sample. The pore pressure in a shear band is an effect of volume changes and filtration of water from the shear band. Generally, at failure, the pore pressure in the shear band is a function of initial moisture, stress level and shear velocity. At failure, the pore pressure is negative for low moisture and low stress level, and positive for high moisture of soil and high stress level. Moisture level, stress level and shear velocity have significant influence on shear resistance of soil.

2

Influence of diaphragm wall installation in overconsolidated sandy clays on in situ stress disturbance and resulting wall deformations

88%

Truty A. A.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2016

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tom 48

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nr 3

3

Impact of soil density on readings of cone penetrometers in soil compaction measurements

75%

Klonowski J.

Annals of Warsaw University of Life Sciences - SGGW. Agriculture

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2016

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nr 68

4

Interactions of azobenzene and microflora in a sandy loam Spodosol

63%

Wackerow-Kouzova N.

International Agrophysics

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2006

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tom 20

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nr 1

5

Field validation of DNDC and SWAP models for temperature and water content of loamy and sandy loam Spodosols

51%

Balashov E., Buchkina N., Rizhiya E., Farkas C.

International Agrophysics

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2014

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tom 28

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nr 2

The objectives of the research were to: fulfil the preliminary assessment of the sensitivity of the soil, water, atmosphere, and plant and denitrification and decomposition models to variations of climate variables based on the existing soil database; validate the soil, water, atmosphere, and plant and denitrification and decomposition modelled outcomes against measured records for soil temperature and water content. The statistical analyses were conducted by the sensitivity analysis, Nash-Sutcliffe efficiency coefficients and root mean square error using measured and modelled variables during three growing seasons. Results of sensitivity analysis demonstrated that: soil temperatures predicted by the soil, water, atmosphere, and plant model showed a more reliable sensitivity to the variations of input air temperatures; soil water content predicted by the denitrification and decomposition model had a better reliability in the sensitivity to daily precipitation changes. The root mean square errors and Nash-Sutcliffe efficiency coefficients demonstrated that: the soil, water, atmosphere, and plant model had a better efficiency in predicting seasonal dynamics of soil temperatures than the denitrification and decomposition model; and among two studied models, the denitrification and decomposition model showed a better capability in predicting the seasonal dynamics of soil water content.

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Reakcja drobnoustrojów i enzymów na zanieczyszczenie gleby miedzią

51%

Kaczynska G., Szudrewicz A., Hawryluk U., Strachel R.

Zeszyty Problemowe Postępów Nauk Rolniczych

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2011

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tom 567

W pracy określono wpływ zanieczyszczenia gleby miedzią na liczebność drobnoustrojów oraz aktywność enzymów glebowych. Doświadczenie wykonano w 3 powtórzeniach w warunkach laboratoryjnych. Do badań wykorzystano glinę piaszczystą o pH 6,7. Czynnikami zmiennymi były: 1) stopień zanieczyszczenia gleby: 0, 130, 260 i 520 mg Cu²⁺·kg⁻¹ gleby; 2) wapnowanie gleby odpowiadające: 0, 2 i 4 jednostkom kwasowości hydrolitycznej; 3) czas inkubacji gleby: 10 i 120 dni. Próbki gleby inkubowano w temperaturze 25°C i wilgotności równej 50% maksymalnej pojemności wodnej. W 10. i 120. dniu trwania doświadczenia określono liczebność grzybów, promieniowców, bakterii organotroficznych i bakterii z rodzaju Azotobacter oraz oznaczono aktywność enzymów: katalazy, dehydrogenaz, ureazy, fosfatazy kwaśnej, fosfatazy alkalicznej, β-glukozydazy i arylosulfatazy. W wyniku badań stwierdzono negatywny wpływ wzrastającego zanieczyszczenia gleby miedzią na liczebność Azotobacter oraz aktywność enzymów, natomiast nie zaobserwowano istotnego wpływu alkalizacji środowiska glebowego na aktywność dehydrogenaz, β-glukozydazy, arylosulfatazy i katalazy.

7

Dynamics of mineral nitrogen release and soil self-cleaning processes after applying farmyard manure and sewage sludge

51%

Gondek K., Chmiel M.

Electronic Journal of Polish Agricultural Universities. Series Agronomy

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2006

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tom 09

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nr 4

8

Dynamic and cyclic static loading behavior of silty-sandy clay at small and moderate strains

51%

Gabrys K., Sas W., Sobol E.

Acta Scientiarum Polonorum. Architectura

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2016

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tom 15

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nr 4

The shear modulus (G) is one of the key parameters for seismic ground response analysis and it can be usually determined by means of dynamic tests (DT), such as resonant column test (RCT), or cyclic static test (CST), e.g. torsional shear (TST). The RC and TS tests are widely used laboratory methods to find stiffness of soil at small to medium strain range (0.0001–0.5%). The purpose of this paper is to present the experimental results from RC and CS laboratory tests on silty-sandy clay from the western part of Warsaw, Poland. The study aims to compare the shear modulus values obtained from two different research techniques. The influence of, in particular, the applied effective pressure, associated shear strain and experimental method (i.e. loading frequency and output amplitude) on the shear modulus at small strains (Gmax) and secant shear modulus (G) are investigated and proved. Generally, the results reveal that the examined soils stiffness calculated from TS tests is lower than from RC tests.

9

Legume cover crop and management influence on conservation till planted corn

51%

Wright D. L., Wiatrak P. J., Pudelko J. A.

Bibliotheca Fragmenta Agronomica

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1997

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tom 2B

10

Nitrogen leaching in different tillage systems

45%

Stenberg M., Aronsson H., Linden B., Rydberg T., Gustafson A.

Bibliotheca Fragmenta Agronomica

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1997

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tom 2B

Ograniczanie wyników

Rate effect on the shear resistance of sandy clay in direct shear tests

Influence of diaphragm wall installation in overconsolidated sandy clays on in situ stress disturbance and resulting wall deformations

Impact of soil density on readings of cone penetrometers in soil compaction measurements

Interactions of azobenzene and microflora in a sandy loam Spodosol

Field validation of DNDC and SWAP models for temperature and water content of loamy and sandy loam Spodosols

Reakcja drobnoustrojów i enzymów na zanieczyszczenie gleby miedzią

Dynamics of mineral nitrogen release and soil self-cleaning processes after applying farmyard manure and sewage sludge

Dynamic and cyclic static loading behavior of silty-sandy clay at small and moderate strains

Legume cover crop and management influence on conservation till planted corn

Nitrogen leaching in different tillage systems