Wyniki wyszukiwania - BazTech

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Biogaz i nawozy w Łebie. Odzysk z myślą o środowisku

Mroczek Magdalena, Chmielewska Iwona

Wodociągi - Kanalizacja

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2024

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nr 11

32--37

2

Effect of fibre content on the geotechnical properties of peat

Chmielewska Iwona

Studia Geotechnica et Mechanica

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2023

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Vol. 45, nr 2

133-143

EN

The purpose of the study was to determine the geotechnical properties of peat and relate them to the fibre content. Peat soil tested in this study was collected from the peatland in the north-eastern Poland, 250 km north-east of Warsaw. Peat samples were taken from eight different depths below the ground surface over an area of approximately 2500 m2. The research programme consisted of laboratory tests of the physical properties of peat and compressibility tests conducted in oedometers. Tests were performed in accordance with the current international and European standards using specialised research equipment. Based on the degree of decomposition, peat was divided into fibric (with more than 66% of fibres), hemic (fibre content from 33% to 66%) and sapric (less than 33% of plant fibres). The bulk and particle densities, natural water content, organic content, initial void ratio and the degree of decomposition were investigated as the physical properties of peat. Based on the oedometer tests, the constrained modulus, compression and secondary compression indexes were determined. It was concluded that the fibric peat is characterised by the lowest bulk and particle densities, the highest water and organic contents, void ratio and compressibility in comparison to hemic and sapric peat. The characteristics of peat have been related to the results presented in the literature.

3

Determination of mechanical properties of soils based on CPTU data

Chmielewska Iwona

Architecture Civil Engineering Environment

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2023

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Vol. 16, no. 3

55--64

EN

The study aimed to interpret the results of cone penetration tests with pore pressure measurement (CPTU). Tests were performed on a section of the designed road about 200 m long. The subsoil under consideration was characterized by organic soils deposited to a depth of approximately 8 m. Due to the problematic soil and water conditions, improvement with geosynthetic encased columns (GEC) was performed. According to the Recommendations for Design and Analysis of Earth Structures using Geosynthetic Reinforcements – EBGEO, the constrained modulus Eoed and effective friction angle φ’ of soil below the GEC column base should be higher than 5 MPa (Eoed > 5 MPa) and 30° (φ’ > 30°), respectively. In this study, the Eoed and φ’ parameters were determined based on CPTU tests conducted in 12 locations. Analysis of the CPTU data showed that the constrained modulus and effective friction angle of the soil deposited below the GEC column base did not meet EBGEO requirements in most locations. It was also concluded that the minimum value of the constrained modulus required by EBGEO is too low compared with the requested value of the effective friction angle.

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Sustainable soil stabilization: the use of waste materials to improve the engineering properties of soft soils

Chmielewska Iwona, Gosk Wojciech

Inżynieria Bezpieczeństwa Obiektów Antropogenicznych

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2022

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Nr 3

34--41

EN

One of the biggest challenges of recent civil engineering is the need to make it sustainable by implementing environmentally friendly and cost-effective solutions. The search for new materials and technologies is an important and current issue also in the strengthening of soft soils. In the soft soil stabilization process, conventional materials (cement and lime) are being replaced by waste materials, such as stone slurry waste, spent coffee grounds, rice husk ash, crushed waste concrete and glass, natural fibers, sawdust, waste tire rubber and plastic waste materials. Appropriate waste admixture content contributes to soil reinforcement by reducing compressibility and increasing maximum density and shear strength. The application of waste as an admixture is an economically and ecologically beneficial method of soil improvement. It eliminates the cost of materials and helps to reduce the problem of waste disposal, which is sometimes very expensive and problematic. The study aims to analyze the effect of waste materials on improving the physical and mechanical properties of soils based on the research results presented in the literature.

5

Wpływ plam słonecznych na opady w Polsce

Chmielewska Iwona, Dołżyk-Szypcio Katarzyna, Szypcio Zenon

Magazyn Autostrady

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2020

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Nr 3

58--64

PL

W artykule pokazano, że na znacznym obszarze Polski sumaryczny opad roczny zależy od liczby plam słonecznych. Wystąpienie powodzi i intensywnych opadów jest bardziej prawdopodobne w okresach małej aktywności słońca niż dużej. Fakt ten może być wykorzystany przy planowaniu budowy dróg i mostów.

EN

The article demonstrates that in a significant area in Poland the total annual precipitation depends on the number of sunspots. Floods and heavy rainfall are more likely during the periods of low rather than high sun activity. This fact can be used when planning the construction of roads and bridges.