Wyniki wyszukiwania

1

Determination of water retention characteristics of organic soils, using the indirect filter-paper method

100%

Oleszczuk R., Zajac E., Hewelke E., Wawer K.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2018

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tom 17

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nr 2

The paper describes the filter-paper method as an indirect method for the estimation of the pF characteristics. In this method, no direct measurements of soil water potential (pF) are performed, but the latter is determined on the basis of the gravimetric moisture content of the filter paper, which is in contact with the analysed soil samples. Therefore, there is a need to establish a calibration equation that would express the relationship between the value of the soil water potential (pF) and the gravimetric moisture content of the filter paper. The calibration procedure was performed using standard measurement methods of determining pF curves (sand box, pressure plates) and filter paper (Whatman no 42). Based on the research conducted, calibration curves were developed for the filter-paper method, for the analysed sapric (drainic) histosoles, developed from moss and alder peats of medium (hemic) and strong (sapric) degree of decomposition, originating from the mid-basin of the Biebrza river. The proposed calibration curves were presented as 3-degree polynomial equations. The aforementioned equations can be used for the estimation of retention characteristic for sapric (drainic) histosoles, showing similar properties and comparable degree of secondary decomposition of the peat mass.

2

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Study on potential of soil stabilization using concrete sludge of batching plant (CSBP)

88%

Nawi N. M., Mat Yusof D. A., Sharipudin S. S., Mohd Halim N. F., Mohamad N. M.

Przegląd Naukowy. Inżynieria i Kształtowanie Środowiska

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2021

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tom 30

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nr 4[94]

3

Test embankments on organic soils

88%

Garbulewski K.

Annals of Warsaw Agricultural University. Land Reclamation

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1986

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tom 22

4

The analysis of consolidation in organic soils

88%

Gabrys K., Szymanski A.

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

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2010

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tom 42

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nr 2

This paper is devoted to the specific difficulties connected to construction on problematic soils. Different type of structures like: road embankments, flood control levees, dykes and dams are often located in soft subsoil areas, which consists mainly of peat, calcareous soil with a very high content of calcium carbonate and other high plasticity organic and no organic soils. These soils can be characterized as highly deformable with low initial shear strength and an insufficient bearing capacity. Soft soils show a large deformation, both vertically and horizontally, under load. The settlements often appear very quickly and can also continue for a long time. The consolidation process consists here of two main stages: primary settlement and secondary (and tertiary) settlement (creep). It is essential to have a good quality description of physical and mechanical properties of soil before the calculation and construction stage. For calculations of each stage of settlement the different physical and mechanical parameters of problematic soil are applied. In this paper the analysis of organic soils deformation process is presented. The deformation characteristics were defined on the basis of laboratory tests results. Soil investigations were performed on peat samples taken from test site located in Olsztyn region. Laboratory test of physical properties and consolidation tests in oedometer were carried out. Based on laboratory test results the empirical relationships between stress and deformation as well as stress and time were elaborated in order to describe the primary consolidation in organic soils.

5

The use of dilatometer test for the determination of undrained shear strength in organic soils

88%

Rabarijoely S.

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

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2008

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tom 40

6

Vertical and horizontal permeability measurements in organic soils

88%

Malinowska E. E., Szymanski A.

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

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2015

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tom 47

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nr 2

The paper is referring to vertical and horizontal laboratory permeability measurements in soft organic soils. The estimation of anisotropic permeability in soft organic soils, as peats, requires to use a special apparatus and the knowledge of proper analysis of the test results. During loading the void ratio decreases substantially that causes the changeability of the permeability. The change of permeability during the compression is very important because of the infl uence of the consolidation coefficient. Initial strain in soft organic soils appears very quickly, just after loading, and brings immediately the decrease of permeability. In most of the estimations, it is assumed that during the consolidation process the water flows just in the vertical direction. In soft organic soils, like peats, the consolidation theory should consider the changes of mechanical and physical properties in consolidation period, in both directions. The direct measurement of vertical and horizontal permeability of organic soil and the non-Darcian flow theory may be of considerable importance in estimating pore water pressure dissipation, and settlement rates in the consolidation model. In the paper, the method of investigation and the test results of the vertical and horizontal permeability are presented. The Modifi ed Rowe Cell Set for obtaining consolidation and fl ow characteristics in different directions is used.

7

Determination of the coefficient of consolidation in soft organic soils using ACONS

88%

Malinowska E.

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

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2012

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tom 44

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nr 2

To determine the coefficient of consolidation using oedometer laboratory tests usually two common methods are used, Casagrande and Taylor. In the paper, the ACONS apparatus and ClispStudio program is characterized. The methodology and the test results of determination coefficient of consolidation in soft organic soils are presented. In the paper, the laboratory test results obtained from Automatic CONsolidation System are analyzed and the relationships between coefficient of consolidation, void ratio, and vertical stress are also presented.

8

New chart for classification of organic soils from dilatometer tests (DMT) results

88%

Rabarijoely S.

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

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2013

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tom 45

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nr 2

To identify the type of soils in subsoil profile from the dilatometer (DMT) tests the diagram charts are commonly used. Marchetti (1980), Marchetti and Crapps (1981) proposed the diagram chart based on the values of material index (ID) and the dilatometer modulus (ED). This chart is helpful for identifying both mineral (clay, silt and sand) and organic soils. The classifi cation to identify organic soils is not accurate enough. This paper proposes a new classifi cation chart for organic soil identification. It was developed based on the comprehensive investigation of organic sediments performed in the Department of Geotechnical Engineering of Warsaw University of Life Sciences in years 1980–2012.

9

Variability assessment of undrained shear strenght of organic soils obtained from field vane tests

75%

Lechowicz Z., Batory J., Hyb W.

Annals of Warsaw Agricultural University. Land Reclamation

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2004

|

tom 35a

10

The influence of smear effect on the consolidation of organic soils

75%

Szymanski A., Lechowicz Z., Wolski W.

Annals of Warsaw Agricultural University. Land Reclamation

|

1986

|

tom 22

11

Content of potassium and magnesium in organic soils and meadow vegetation of Szczecin Pomerania

75%

Niedzwiecki E., Protasowicki M., Meller E., Malinowski R., Sammel A.

Journal of Elementology

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2009

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tom 14

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nr 2

331-340

The studies included the major organic meadow soils of Szczecin Pomerania, left fallow or sporadically used extensively. The following determinations were made: the content of plant available magnesium and potassium (using HCl at the concentration of 0.5 mol⋅dm- 3), their total forms (soluble in the mixture of concentrated acids HNO3 + HCIO4) as well as the content of potassium and magnesium in the meadow-pasture sward from the area under study. The results are presented in Table 1. The investigated peat-muck, gyttiamuck, mineral-muck and muckous soils, in the surface layer 0-30 cm deep (which was primarily the muck layer) mostly contained the amounts of potassium and magnesium typical of organic soils when soluble in the mixture of concentrated acids HNO3+HCIO4 but low and frequently very low amounts of potassium soluble in 0.5 mol⋅dm-3 HCl from (0.04 to 0.51g⋅kg-1). The content of this form of potassium depended on the degree of peat siltation. Low resources of available potassium were caused by the deficiency of this element in the meadow pasture sward since only in the sward of the Gryfinski Polder in Miedzyodrze and the sward from gyttia-muck soils near Miedwie Lake the optimum amounts were detected (above 15.0 g⋅kg-1 dry matter). In comparison with these results, the content of magnesium, soluble in 0.5 mol⋅dm-3 HCl in these soils was more favourable to plants (generally above 0.40 g⋅kg-1), which is considered high according to the Institute of Soil Science and Plant Cultivation (IUNG 1990). In meadow sward, magnesium content mostly exceeded 2.0 g⋅kg -1 dry matter so either approached or reached the optimum value for fodder. Despite this, the calculated K:Mg ionic ratios confirm an unfavourable fodder value.

12

Estimation of lowland river cross-section changes for different soils

75%

Urbanski J., Oleszczuk R., Brandyk A., Zajac E.

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

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2018

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tom 50

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nr 4

13

The small strain stiffness from bender elements tests for clayey soils

75%

Markowska-Lech K., Sas W., Gabrys K., Lech M., Szymanski A.

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

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2018

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tom 50

|

nr 4

14

The overconsolidation ratio of eemian gyttja determination

75%

Bajda M., Malinowska E. E.

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

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2017

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tom 49

|

nr 3

15

Derivation of consolidation partial differential equations with non-linear flow characteristics on organic soil example

75%

Malinowska E. E., Bursa B. A., Szymanski A.

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

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2014

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tom 46

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nr 4

Derivation of consolidation partial differential equation with non-linear flow characteristics is proposed. The non-linear flow characteristics are obtained from flow-pump test on organic soil and described with empirical relationship. Several reasons were crucial to perform tests on organic soil. Firstly organic soils are very compressible, so that results in high permeability changes. Even with small stresses organic soil deforms a lot. Secondly road embankments, flood control levees, dykes and dams are very often located on organic soil, so it is important to model deformations under these constructions. Thus to model consolidation process in soft organic soil one should consider as follows: physical and mechanical properties, non-linear stress-strain relationship, non-linear flow characteristics, and creep strains. This paper is focused mainly on non-linear flow characteristics that change with porosity and hydraulic gradient variations.

16

The influence of dewatering and reclamation on water retention of peat soils in the sandy outwash landscape

75%

Piascik H., Lachacz A.

Polish Journal of Soil Science

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1997

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tom 30

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nr 2

17

Investigations of the consolidation of gyttja

63%

Krol P., Lechowicz Z., Szymanski A.

Annals of Warsaw Agricultural University. Land Reclamation

|

1986

|

tom 22

18

Analysis of thermal diffusivity data determined for selected organic topsoil layer

63%

Gnatowski T.

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

|

2009

|

tom 41

|

nr 2

95-107

19

Phosphorus forms in organic soils with a varying degree of transformation [on the example of the Lublin Polesie region]

63%

Ziolek M.

Polish Journal of Soil Science

|

2007

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tom 40

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nr 2

179-194

The aim of the present study was to evaluate the content of various phosphorus forms in organic soils with various transformation degrees as well as to determine the distribution of the total phosphorus pool into its individual soil forms along with their location in the soil profiles. Three soil profiles originating from peats and collected from areas subjected to the influence of various human activities, located in the Lublin Polesie region, were the subject of the present research. A method of sequential phosphorus fractioning was applied. Three fractions of inorganic phosphorus: Pi-L – labile inorganic P, loosely adsorbed; Pi-FeAl – inorganic P associated with Fe and Al; Pi-CaMg – inorganic P associated with Ca and Mg; and two fractions of organic phosphorus: Po-HuAc – organic P associated with fulvic and humic acids, and Po-Res – residual organic P. The following conclusions can be drawn from the present research: in the soils from the areas strongly transformed by man (completely dehydrated and with an advanced muck formation process) accumulation of total phosphorus in the upper part of the soil profile takes place, accompanied by a decrease of organic forms content and an increase in the share of inorganic phosphorus forms; forest peat soil not subjected to a direct influence of human activities was characterised by a very high total phosphorus content; the distribution of the total phosphorus pool into individual fractions in organic soils mainly depends on natural conditions such as: peat-bog character, carbonates content, and pH.

20

Heavy metals in the organic soils and tissues of forest floor plants in alder carr sites of Kampinos National Park

63%

Okolowicz M.

Annals of Warsaw Agricultural University. Agriculture

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2001

|

nr 39

59-69

Ograniczanie wyników

Determination of water retention characteristics of organic soils, using the indirect filter-paper method

Study on potential of soil stabilization using concrete sludge of batching plant (CSBP)

Test embankments on organic soils