Šarūnas Skuodis

Experimental and numerical investigation of sand compression peculiarities

Abstract Investigation of the compression properties of Klaipėda sand by oedometric testing and numerical modeling is presented. Klaipėda sand is characteristic of the Baltic seashore region sand. Experimental investigation was performed with fraction corresponding to diameter variation bounds of 0.6 and 0.425 mm. Compression test was realized with initial maximal void ratio (e 0 = 0.800) of sand. Employed vertical stress ramp value is 800.0 kPa/min, maximum loading σmax = 400.0 kPa. Applying loading within the range of 50.0 to 120.0, two vertical stress jumps have been identified. A rubber sample compression test has been performed aiming to deny an assumption, that vertical stress jumps are influenced by device construction. Experiment viewed that not any vertical stress jumps have been recognized. Numerical simulation yielded exactly the same two vertical stress jumps found by compression with oedometer. It proves that the nature of rearrangement of sand grains has been properly reflected by modeling c...

Grunto, armuoto geotinklais, kerpamojo stiprio tyrimai

Straipsnyje apžvelgtos grunto kerpamojo stiprio savybės, kai gruntui armuoti yra naudojami geotinklai. Pastaruoju metu sis metodas Lietuvoje yra placiai taikomas statybų srityje, tiesiant kelius ir geležinkelius. Triasio slėgio bandymuose tirti vieni is dažniausiai grunto armavime naudojamų lankscių ir standžių geotinklų, kurių stipris tempiant isilgai ir skersai ≥40 kN/m. Gauti pikinių ir liekamųjų kerpamojo stiprio rezultatai palyginti su nearmuoto grunto, atliktas palyginimas tarp standžiais ir lanksciais geotinklais armuotų bandinių. Nustatyta, kad geotinklų naudojimas armuojant grunto kompozitines konstrukcijas pagerina armuotų konstrukcijų savybes, palyginti su nearmuotomis.

Determining characteristic sand shear parameters of strength via a direct shear test

AbstractThe article considers the peculiarities of determining quartz sand shear strength according to the Mohr-Coulomb strength criterion, via a direct shear test and that of factors influencing the characteristic angle of internal friction and cohesion values of the obtained strength parameters. The air-dry sand of the Baltic Sea region from Lithuanian coastal area near Klaipėda city has been analyzed. The solid density of the investigated sand grains was ρs=2.65 g/cm3. The initial density of the tested samples made ∼1.48–1.50 g/cm3. Processing data on the shear test yielded that the quantity of 18 tests was sufficient for the relevant accuracy of determining characteristic sand shear parameters of strength. This quantity of tests allow avoiding the influence of statistical coefficient tα that depends on a degree of freedom (K=n – 2). The paper presents additionally analyzed three different approaches to determining the characteristic shear parameters of strength and that of a comparative analysis of th...

Experimental investigation of clay-straw building finishing layer under different drying conditions

AbstractThis manuscript represents investigation of six different clay mixtures under variable drying conditions, namely: bright yellow clay (typical for Lithuania), brown clay (Lithuania Sergėnai district), mixture of different clays, white Spanish clay, clay mass which is resistant for thermal coldness (with synthetic cardigan) and Lithuanian coarse clay with granite additives. Drying process was provided imitating natural drying process and fast drying in drying oven at 110 C°. The main idea of this study – imitate clay and clay-straw buildings drying process and to determine which of used clay types had smallest volumetric and linear deformations. Volumetric and linear deformations for clay-straw buildings is one of the most important factors evaluating cracking in this type of buildings. To reach this purpose six tiles of different clay types were used. Before drying stage water content, plasticity, and liquid limits index, respectively was determined for all types of clay. All clay tiles volumetric ...