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In the framework of reconstruction of the Old Bridge, two exploratory wells were made in the channel of the Danube River. The depth of the exploratory wells was up to 55 m below the modified terrain around the bridge pillars. The role of the exploratory wells was verifying the thickness of Quaternary sediments and simultaneously verifying Neogene soils properties located in the channel of the Danube River. The exploratory wells verified that the Neogene subsoil of the Danube River is predominantly made up of silty-clayey soils of intermediate to hight plasticity locally alternated by sandy positions. The paper presents the results of experimental measurements not only index characteristics, but also the shear strength and compressibility parameters of Neogene soils forming the subsoil of the Danube River in Bratislava. The paper presents in detail range of grain composition of Neogene soil samples, location of Neogene soil samples in plasticity diagram, the average shear strength parameters of individual types Neogene soils, the average shear strength parameters of all samples Neogene soils, example evaluation of oedometer compressibility test of Neogene soils, change oedometric modules of Neogene soils depending on the sampling depth. The functional dependencies of the change of oedometric modules with the depth of sampling from the Neogene subsoil are expressed. Experimentally verified parameters of the Neogene subsoil served for the design of the reconstruction of the pillars of the Old Bridge across the Danube River in Bratislava. [ABSTRACT FROM AUTHOR]

This paper is a report on the results of a feasibility study on the immobilization of municipal solid waste incinerator fly ash by producing a fired clay brick. The main purpose of this work was to test the clay used in the manufacture of a fired clay brick that could incorporate municipal solid waste incinerator fly ash. The raw materials, municipal solid waste incinerator fly ash and clay, were mixed together in different proportions (100:0, 97.5:2.5, 95:5 and 92.5:7.5). Clay brick samples were heated to 1000 °C temperatures for 1 h. The fired clay brick specimens were characterised with respect to compressive strength, porosity, linear shrinkage (after drying, after firing) and density. Leaching tests, in accord with the European Union regulation, was done on fired clay brick made with different additions of municipal solid waste incinerator fly ash. [ABSTRACT FROM AUTHOR]

Angle of friction φ, cohesion c and undrained shear strength τfu are the strength parameters that characterize the mechanical properties of soils. These parameters determine the bearing capacity of a cohesive subsoil. The value of strength parameters depends on many factors, e.g. soil type, consistency, stress state, stress history, loading type and loading mode. The paper presents the influence of plasticity index Ip on strength parameters in cohesive soils. To determine the dependence of strength parameters on the plasticity index a lot of tests in a triaxial apparatus on overconsolidated cohesive soils characterized by a plasticity index Ip in the range from 10% to 79% were carried out. Triaxial tests were performed in isotropic consolidation and shearing of soil samples in drained and undrained conditions. Based on the test results the analysis of the relationship between strength parameters (the angle of internal friction, cohesion, normalized undrained shear strength) and plasticity index were presented in respect to the used standards and literature. [ABSTRACT FROM AUTHOR]

Field vane shear test (FVT) is one of the popular methods in the world to determine in-situ undrained shear strength of clayey soil, however it is not popular in Japan. A series of soil investigation including FVT has been conducted at coastal area in Japan. Laboratory tests such as index tests, direct shear test (DST) and unconfined compression test were also carried out using undisturbed samples which were taken using Japanese type hydraulic sampler with fixed piston. In this paper, undrained shear strengths from FVT are compared with results from DST, which recompression method is applied to determine in-situ undrained shear strength. Subsequently, correlation between undrained shear strength and plasticity index is explained. In addition, the relation of clay at Onsøy in Norway, Louiseville in eastern Canada and Mexico City are also studied and discussed. [ABSTRACT FROM AUTHOR]

Isotropic packings of cohesive disks in 2D are studied by discrete, stress-controlled numerical simulations. Depending on the assembling process and on whether contacts possess rolling resistance (RR), configurations form under low pressure P with varying solid fraction [uppercase_phi_synonym] and fractal dimension dF describing small scale correlations below some blob size ξ. The gradual collapse observed under growing P is described as a linear relation between lnP and 1/[uppercase_phi_synonym] within some range, once the influence of initial conditions has faded out, and until a maximum density is approached. This corresponds to a decrease of ξ that is compatible with the fractal blob model. The isotropic tensile strength is always considerably smaller than the naive Rumpf estimate, and grows with consolidation. Coordination numbers in systems with small RR change little while density increases by large amounts in consolidation. [ABSTRACT FROM AUTHOR]