Papers by Keyword: Soil

Abstract: The climate change prognosis in the Kharkiv region shows an increasing danger of forest fires and negative consequences for the environmental components. In this article the negative impact from forests fires on the environment have been analyzed. The new method is proposed for cleaning the surface runoff, which is formed after a forest fire, by filtering in artificial or natural through the biological trenches using basalt chips of 0,5–2 mm in size as a filtration nozzle. Use of the proposed method of surface runoff purification will improve the water ecosystem sanitation and the increase of the ecological safety due to the production company wastes utilization. The proposed method of stormwater treatment is easy to operate, ecologically friendly and economically advantageous.

Abstract: The paper briefly describes the methods for testing soils by triaxial compression. Among the many mechanical characteristics of the soil, deformation and strength properties remain as the main and widely used ones, the determination of which is an important experimental task. In recent years, new test schemes, more advanced designs of instruments and equipment for the study of various soils have been proposed. Like any material, the soil has limited strength, and under certain external influences the soil massifs collapse, as a result of which their individual parts get unlimitedly large displacements. Triaxial soil compression is becoming more widespread in the production of engineering and geological studies to justify the construction projects of various engineering structures. Based on the results of this work, recommendations for the practical application of the obtained soil characteristics for the geotechnical geoinformational database of the city of Nur-Sultan are made.

Abstract: A modified Mohr – Coulomb criterion is presented. This criterion, in addition to adhesion and the angle of internal friction, contains the third parameter of the material (d). Depending on the value of this parameter (d), the modified criterion can take the form of the original Mohr – Coulomb criterion (with d = 0.5) or the original Treska criterion (with d = 0). For all other values of the parameter (d), varying in the range of 0 <d <0.5, the tangential stresses by the modified criterion are larger than the Mohr – Coulomb criterion, but less than the Tresca criterion. The paper presents the methodology and results of determining this parameter (d) using experiments on the triaxial compression of soils. The technique contains recommendations for the appointment the value of the axial strain of the sample material when determining the value of the parameter d. The value of the ultimate deformation is advisable to take in the range from 8 to 12%. This range is due to the fact that with axial deformation of the sample of 8%, the formation of slip areas begins in it, and with axial deformation of the sample 12%, the slip area is completely formed. In this case, the parameter d varies in the range 0 <d <0.5, having a shear strength bigger than in the Tresca criterion, but less than in the original Mohr – Coulomb criterion. The tangential stresses according to the modified criterion, on the contrary, have a bigger value than according to the Mohr – Coulomb criterion, but the values of the tangential stresses are lower than in the Tresca criterion.

Abstract: The paper presents the results of the evaluation of the environmental potential of soils in the area affected by the long-term mining activity. The environmental potential index consists of a numerical expression of the ability to provide water storage, immobilization of risk elements, and immobilization and transformation of organic pollutants. The exceedance of the limit values Hg, Cu, Zn, As, Cd and Pb was found in the soils of the investigated area of central Spiš. The rate of soil immobilization of risk elements is very low to high. The point value expressing the ability of agricultural lands to provide environmental functions is very low to medium in the studied areas, the financial expression of the values of the environmental potentials indexes is in the range of 7 100 to 14 000 € ha^-1, while the average value of 1 ha of agricultural land in Slovakia is about 14 200 €.

Abstract: In the framework of this study, compressed earth blocks (CEB) were produced using waste materials and various parameters. Material parameters included waste soil, recycled concrete, fly ash, cement, admixtures and water contents. Manufacturing parameters were vibration during manufacturing, confinement pressure, curing environment and curing time. Specimens used in this study were cubes and compressive strength testing was used to evaluate different mixtures and manufacturing methods. In terms of compressive strength, compressed earth blocks made of these materials could be used for manufacturing bricks and other structural elements.

Abstract: To explore the soil fertility and tea quality and yield during the process of replacing chemical fertilizer with organic fertilizer, we established three experiment groups: experimental group I (formulated fertilization and biogas slurry), experimental group II (habitual fertilization) and experimental group III (formulated fertilization). Comparing with soil fertility, quality and heavy metal contents in fresh leaves among three groups in five tea gardens of Mingshan District, explores the effects of three different fertilization treatments on. The results showed that the experimental group I and experimental group III could improve soil fertility (including increasing the organic matter, total nitrogen and alkali-hydrolyzable nitrogen content) compared with the experimental group II. On the Fresh leaf yield, experimental group I> experimental group III > experimental group II(P<0.05), in which experimental group I was 27.26% higher than experimental group III. On yield, different treatments had less effect on the main quality components of fresh leaves (P>0.05).Compared with the experimental group II and the experimental group III, the heavy metal content of the experimental group I was higher, but no more than the food safety standard limit. In summary, experimental group I and experimental group III can effectively improve soil fertility and fresh leaf yield compared with conventional fertilization, particular experimental group I.

Abstract: Limited connectivity and poor infrastructure of roads acts as a roadblocks hampering the socio-economic development of one region. In order to overall development of these regions an effort should be given to cultivate well established road network. But due to scarcity of good quality soil PWD engineers are often forced to build roads over the weak soil which directly affects the strength and durability of the road. It is therefore essential to improve the engineering properties of such problematic soil with suitable stabilization technique as and when encountered. Lime stabilization is one such well known chemical stabilization technique extensively used to improve the poor subgrade condition and it is recommended by several codes in INDIA. This paper attempts to study the effect of lime on strength and bearing capacity improvement of soft clayey soil. A series of UCS and CBR tests are conducted with different percentages of lime (i.e. 3, 5, 7 and 9%) and at different curing period to assess the potential of lime in strength improvement. Test results indicate that strength, stiffness and bearing capacity of the soil is considerably improved after lime amendment. Both unconfined compressive strength (UCS) and California bearing ration (CBR) improved up to 7% of lime beyond that it decreases. The improvement of UCS and CBR is found approx three and five fold as compared to original soil. Underlying mechanisms of this improvement is further scrutinized by microstructural analysis such as X-ray diffraction (XRD), Field Emission scanning electron microscope (FESEM) with Energy dispersive X-Ray Analysis (EDAX). Apparent formation of some new peaks in XRD analysis and change of textural and structural morphology of clayey soils obtained from FESEM confirms the formation of cementitious compounds in the lime stabilized soil.

Abstract: Paper observes research of the mechanical characteristics of the stabilized soil with different «Chimston» additives. Current work focuses on the application of the «Chimston-1» and «Chimston-2» produced by Zipo research and production company. Stabilized soil is based on local soils: argillaceous sand ground and sand clay. Chemical additives are mixed with water according to the manufacture’s recommendations. Amount of the «Chimston-1» is 0.07% of the soil. Amount of the «Chimston-2» is 0.01% of the cement. During the research plasticize effect is studied, based on maximum density and optimal humidity. Water saturation, mechanical strength under tension in bending and compression. It is established, application of the "Chimson" additives allow to increase key characteristics of the stabilized soil without increasing of the cement. «Chimston-1» additive has strongly pronounced plasticize effect which allow to increase soil compaction and decrease optimal humidity. Additive "Chimston-2" is a water repellent with a high degree of efficiency with soil stabilization.

Abstract: Steel sheet pile wall corrosion in soils and water is a complex phenomenon. The deterioration of these structures is costly and difficult to predict. The aim of this paper was to deal some empirical corrosion models which are analyzed and compared to Eurocode 3, Part 5 to estimate corrosion rate and the loss of thickness of anchored steel sheet pile wall. The results show that care should be taken to ensure that the maximum bending moments do not occur at the same level as the main corrosion zones. Furthermore, it is possible to define an upper and a lower bound, corresponding respectively to the presence of sea water in low water and the undisturbed natural soils, in order to predict the loss of thickness due to corrosion.

Abstract: The article discusses the photochemical effects of sunlight on the soil. Under the influence of light energy the amount of mineral and easy hydrolysable nitrogen, as well as labile humus substances increased in the soil. The photochemical destruction of humus substances was accompanied by an increase in their mobility and loss of colour. The article shows that the process of mineral nitrogen formation in the soil during the photochemical destruction of humus substances has two stages. The first stage includes photochemical reactions with the formation of ammonium nitrogen. The second stage is the microbiological oxidation of ammonium nitrogen to the nitrate nitrogen.