Vertical and horizontal permeability measurement in organic soils. 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 coeffi cient. 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 fl ows 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 fl ow 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.

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The uncertainty of the water flow velocity data obtained in the laboratory test The uncertainty of the water flow velocity data obtained in the laboratory test. Some of the engineering constructions are significant for the environment and flood protection. There are dams for water retention as well as waste tailings dams and road embankments founded on organic soils. Constructions on soft organic soils make it necessary to calculate subsoil deformations with a special regard of the water flow. In this thesis, the approach of the water flow test in soft organic soils is presented. In the permeability test the modern flow-pump technique was applied. This technique takes into consideration organic fiber structure, large soil strain, short time of research and "real" hydraulic gradients appearing in situ. The specific behavior of soft subsoil demands to calculate the test reliability results. Therefore in the statistical analysis of the test results the suitable statistical method and the proper laboratory technique should be used. Several statistical models have been applied to the flow pump test results in order to find the correct description of water flow velocity in soft subsoil.

Abstract:The overconsolidation ratio of eemian gyttja determination. The overconsolidation ratio is an important parameter that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. Overconsolidation ratio (OCR) is one of the main criteria conditioning soil behavior and characteristics. To know the relation between geological background, history and mechanical behavior of the soil, aims a knowledge that can help engineers who often have to predict soil behavior based upon the soil geological history and a geotechnical data. In order to evaluate the overconsolidation ratio of eemian gyttja, it is necessary to restore this soft soil as much as possible to the in situ conditions. The eemian gyttja is an organic soft soil from the "Zoliborz channel" located in Warsaw. These soils are used as a base construction in the foundation engineering. In practical geotechnical engineering, evaluation of stress history is based on the overconsolidation ratio. The overconsolidation ratio is one of the basic parameters for the geotechnical design of the structure. Determination of this parameter using for example dilatometer tests, is usually based on empirical formulas which were established in different countries. Therefore, regional geotechnical conditions could have substantially affected on the empirical relationships. The laboratory tests are used to determinate the preconsolidation pressure and then the overconsolidation ratio. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the dilatometer test (DMT). The paper presents results of determination the overconsolidation ratio of eemian gyttja from the laboratory and in situ tests. The studies have shown that the values of the overconsolidation ratio determination from the laboratory tests are a little higher than determination from the in situ tests.

W pracy przedstawiono zmodyfikowany system z komorą Rowe’a (MRCS). Dwie główne modyfikacje zostały przeprowadzone: dodano trzeci, pneumatyczny kontroler oraz przełożono górny zawór do pomiaru przepływu poziomego. Dzięki temu, system został przystosowany do badań zarówno konsolidacji, jak i przepływu dla tych samych warunków brzegowych w tym samym czasie oraz do badania przepływów poziomych z możliwością większej precyzji zadawania poziomego drenażu do środka i na zewnątrz próbki gruntu.