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M. A. Hariri-Ardebili and H. Mirzabozorg

Abstract

The Dez dam was commissioned in 1963 and since sediments accumulated in the reservoir up to an elevation of approximately 15m below the intake of the power tunnel. One of the possible measures to improve operation of the reservoir is by heightening of the existing dam. This paper describes the conducted procedure for static and thermal calibration of this 203m dam in Iran based on micro geodesies measurements. Also the nonlinear response of existing dam is investigated under maximum credible earthquake ground motions considering joint behavior and mass concrete cracking and safety of dam is evaluated for possible heightening. For thermal calibration of provided numerical model, transient thermal analysis was conducted and results were compared with thermometers records installed in central block. In addition, for static calibration; thermal distribution within dam body, dam self weight, hydrostatic pressure and silt load applied on the 3D finite element model of dam-reservoir-foundation were considered. Results show that the distribution of stresses will be critical within dam for heightening case under seismic loads in MCL.

Open access

Jarosław Kaszubkiewicz, Witold Wilczewski, Tibor József Novák, Przemysław Woźniczka, Krzysztof Faliński, Jerzy Belowski and Dorota Kawałko

Abstract

Texture is one of the most significant physical properties of soils. Over the years, several methods of its measuring were developed. The paper presents a method for determining the particle size composition of soils, based on the separation of particles in the sedimentation process. Density of suspension is determined on the basis of apparent weight changes of a float submerged in it. The weight of the float suspended on a thin line, at a given depth in the suspension, is measured with a sensitive piezoelectric dynamometer. The Stokes equation is used to calculate the content of soil fractions with equivalent diameters in the range of 0.001 to 0.1 mm. Digital transmission of results from the dynamometer, the temperature sensor and measurements of the distance defining the depth of immersion of the float to the computer enable calculations of particle size composition to be performed automatically. This paper presents the results of measurements of the particle size composition of artificially generated mixtures of ‘silt’ and ‘clay’. The results are compared with results obtained with other methods (including the laser method). A high level of repeatability of the results and satisfactory compatibility in relation to the reference pipette method are noted.

Open access

Jie Zhao, Lingyun Bao and Guixuan Wang

Abstract

In an artificial island construction project based on the large-scale marine reclamation land, the soil settlement is a key to affect the late safe operation of the whole field. To analyze the factors of the soil settlement in a marine reclamation project, the SEM method in the soil micro-structural analysis method is used to test and study six soil samples such as the representative silt, mucky silty clay, silty clay and clay in the area. The structural characteristics that affect the soil settlement are obtained by observing the SEM charts at different depths. By combining numerical calculation method of Terzaghi’s one-dimensional and Biot’s two-dimensional consolidation theory, the one-dimensional and two-dimensional creep models are established and the numerical calculation results of two consolidation theories are compared in order to predict the maximum settlement of the soils 100 years after completion. The analysis results indicate that the micro-structural characteristics are the essential factor to affect the settlement in this area. Based on numerical analysis of one-dimensional and two-dimensional settlement, the settlement law and trend obtained by two numerical analysis method is similar. The analysis of this paper can provide reference and guidance to the project related to the marine reclamation land.

Open access

Jolanta Cieśla, Zofia Sokołowska, Barbara Witkowska-Walczak and Kamil Skic

Abstract

Water vapour/nitrogen adsorption were investigated and calculated the specific surface areas of arctic-zone soil samples (Turbic Cryosols) originating from different micro-relief forms (mud boils, cell forms and sorted circles) and from different depths. For the characterisation of the isotherms obtained for arctic soils, the Brunauer-Emmet-Teller model was then compared with the two other models (Aranovich-Donohue and Guggenheim-Anderson-de Boer) which were developed from Brunauer-Emmet-Teller. Specific surface area was calculated using the Brunauer-Emmet-Teller model at p p0 −1 range of 0.05-0.35 for the water vapour desorption and nitrogen adsorption isotherms. The values of total specific surface area were the highest in Cryosols on mud boils, lower on cell forms, and the lowest on sorted circles. Such tendency was observed for the results obtained by both the water vapour and nitrogen adsorption. The differences in the values of specific surface area at two investigated layers were small. High determination coefficients were obtained for relationships between the specific surface areas and contents of clay and silt fraction in Cryosols. No statistically significant correlation between the total carbon amount and the values of specific surface area in Cryosols has been found.

Open access

Ágnes Kun, Orsolya Katona, György Sipos and Károly Barta

Abstract

Nowadays there is a growing demand for rapid and accurate determination of grain size distribution. The conventional pipette method is time-consuming and provides less detailed data compared to recently introduced methods. However, in Hungarian practice the pipette method is still considered to be the standard one, as there are a long series of measurements, and grain size thresholds used in sedimentology and soil sciences are based on this approach. The aim of our research was to determine the comparability of the laser diffraction method (LDM) with the conventional pipette method (PM), in order to investigate the controversial question on the interchangeability of the two methods. Based on our measurements on some representative fluvial sediment samples, we found that the largest difference in results can be expected in the silty grain size range. However if the main fractions (clay, silt, sand) are considered the methods provided similar very results, and correlation factors were above 0.92. In all, the LDM has a clear advantage because of its speed, reproducibility and fewer possibilities for operator failure.

Open access

Wojciech Litwin and Artur Olszewski

ABSTRACT

Water-lubricated bearings have been applied to support ship screw shafts for over a hundered years. Development of plastic materials has caused that novel sliding polymers appeared available on the market and being approved by classification institutions, possible to be applied in shipbuilding. However in the subject - matter literature there is no reference to application of bearings fitted with metal or ceramic bushes in shipbuilding. Nevertheless they have important merits such as low resistance to motion, long service life or stability of form. But some doubts are evoked by their large value of shape elasticity module which can lead to local stress concentration at the bush edges in the case of non-axiality of bush and shaft axes. Hence this work has been aimed at the testing of a bearing made of bronze-graphite silter. In the work is presented a comparison of measurement results of resistance to motion , hydrodynamic pressure distributions in lubricating film as well as shaft axis trajectories of the bearing, with those made for a typical elastic polymer bearing. The measurement results have showed high quality of the tested material. In the opinion of these authors it could be applicable to bearing ship propeller shafts.

Open access

Elżbieta Musztyfaga and Cezary Kabała

Abstract

The paper focuses on Glossic Planosols (formerly Albeluvisols) with sandy topsoil widely represented in the northeastern part of Lower Silesia (SW Poland), in the range of tills from the Odra and Warta glaciations (Riss glaciation). The aim of the study was to characterize the texture of these soils in the context of the origin of parent materials and present-day pedogenic processes. Both the sedimentological and granulometric indexes, unbalances clay (and silt) fraction, and ventifact pavement at the contact of underlying loam and topsoil sandy layer confirm, that the textural differentiation of the topsoil and subsoil horizons has not resulted from the pedogenic processes, but primarily from the lithological discontinuity of glacial and post-glacial parent materials. Particle-size distribution and granulometric indexes of albeluvic tongues in the glossic horizon also confirm that the tongues has not been formed by eluviation of the fine fractions from the loamy material, but primarily by filling the initial thin crack with the sandy material. The coarser-textured tongues foster a deep infiltration and stagnation of water, and the development of reductic conditions allows further widening and deepening of the albeluvic tongues.

Open access

Maciej Major

Lithological Differences in the Deposits of Closed Basins in the Upper Parsęta Catchment (Western Pomerania)

Basins without outlets, found in abundance in West Pomerania, display a great lithological diversity. Differences in the lithology in the upper Parsęta catchment result from the processes of areal deglaciation during the Vistulian Glaciation (Karczewski 1989). Intraglacial accumulation, action by fluvioglacial water, and direct glacial accumulation have produced various sedimentary series and their mosaic-like pattern. The youngest sedimentary series have developed during fluvial, aeolian and organogenic accumulation (Kostrzewski et al. 1994a). The lithology of most of the closed basins in the catchment largely features fine diamictic sands which pass into sandy diamicton at 100 cm, then medium diamictic sands which turn into fine sands at depths of 50 and 100 cm, and massive diamictic sands which turn again into sandy diamicton at 100 cm. In the catchment of a closed evapotranspiration basin equipped with measuring instruments, the predominant deposit is sands, especially medium-grained ones. Much less abundant are diamictic sands and sandy diamictons, and silts occur only sporadically. Such a lithological diversity is responsible for different rates of the water cycle recorded in the particular parts of the study area.

Open access

Zbigniew Kaczmarek, Piotr Gajewski, Andrzej Mocek, Wojciech Owczarzak and Bartłomiej Glina

Abstract

The paper presents the characteristics of selected physical, chemical, and water properties of four mineral arable soils characterized with heavy and very heavy texture. Soil samples from genetic horizons of black earths from areas near Kętrzyn, Gniew and Kujawy, and alluvial soils from Żuławy were used. The following properties were determined in the samples of undisturbed and disturbed structure: texture, particle density, bulk density, porosity, natural and hygroscopic moistures, maximal hygroscopic capacity, saturated hydraulic conductivity, potential of water bonding in soil, total and readily available water, total retention in the horizon of 0–50 cm, drainage porosity, content of organic carbon and total nitrogen Parent rocks of these soils were clays, silts and loams of various origin. High content of clay fraction strongly influenced the values of all the analyzed properties. All the examined soils had high content of organic carbon and total nitrogen and reaction close to neutral or alkaline. High content of mineral and organic colloids and, what follows, beneficial state of top horizons’ structure, determined – apart from heavy texture – low soil bulk density and high porosity. The investigated soils were characterized by high field water capacity and wide scopes of total and readily available water. The saturated hydraulic conductivity was low and characteristic to heavy mineral arable soils. The parameter which influenced the variability of analyzed parameters most was texture.

Open access

Paweł Sowiński

Abstract

The aim of this paper was to characterize soil particle-size distribution (PSD) of in the middle part of young glacial Łyna River valley in relation to parent materials, soil forming processes and slope position. The study comprised rusty soils, arenosols, clay-illuvial soils, colluvial and alluvial soils located in four slope position: summit / midslope, footslope / toeslope, upper and lower part of floodplain. In order to describe the sedimentological environment and possible heterogenity of the soil formations, sedimentological and granulometric indices were calculated. The relationships between soil fractions in A horizons and environmental variables (slope position and depth of A horizon) were determined using principal component analysis (PCA).

The studied soils were poorly sorted with various values of skewness of granulometric distribution (symmetrical, fine and very fine skewed) and kurtosis (mainly very leptokurtic). The value of mean grain diameter was decreasing with slope position which may suggest high dynamics and energy of sedimentological environment in the middle part of Łyna River valley. The analysis of granulometric indices revealed that colluvial deposits were the most homogenous and alluvial formations were the most heterogenous. The results of the statistical analysis showed a positive correlation of the amounts of clay and silt fractions with depth of A horizons. The factor responsible for variability of these fractions was the position on the slope. The A horizons in soils located at the summit and footslope had the highest amounts of sand fractions. While significant increase in the share of finer fractions in soils located in the floodplain was noted.