Search results for "Laboratory testing"
showing 10 items of 12 documents
One dimensional consolidation of Opalinus Clay from shallow depth
2017
First experimental results on Opalinus Clay from shallow depth (< 30 m depth) are presented and compared to results on cores from Mont Terri Underground Rock Laboratory (~ 300 m depth). Samples were tested in one dimensional condition using an advanced experimental technique. The samples from the two sites show similar properties in terms of geotechnical characterization and one dimensional compressibility/swelling indexes, despite the different source depths.
Evaluation of Subgrade Resilient Modulus Predictive Model for Use in Mechanistic-Empirical Pavement Design Guide
2006
The characterization of unbound materials in the mechanistic–empirical pavement design guide (MEPDG), also known as the 2002 design guide, is reviewed, and this characterization is applied to Minnesota subgrades. The main emphasis is on the collection of k1-, k2-, and k3-parameters for Minnesota fine-grained soils and the procedure for the interpretation of the resilient modulus test to provide an input to the multilayer elastic theory (MLET) analysis (Level 2 input). This is an important aspect of adaptation of the MEPDG, because the guide recommends measurement of resilient moduli from laboratory testing, but the procedure does not specify how to interpret the test data to obtain an input …
Experimental investigations of the soil–concrete interface: physical mechanisms, cyclic mobilization, and behaviour at different temperatures
2016
Behaviour of the pile–soil interface is important to correctly predict the response of floating piles in terms of displacement and lateral friction. Regarding energy piles, which couple the structural roles of deep foundations with the principle of shallow geothermal energy, the response of pile–soil interfaces is influenced by seasonal and daily cyclic thermal variations. Accordingly, the goal of this paper is to experimentally investigate the response of the pile–soil interface at different temperatures. This experimental campaign aims to analyse (i) the cyclic mobilization of the shear strength of the soil–pile interface that is induced by thermal deformation of the pile and (ii) the di…
1D Compression Behaviour of Opalinus Clay
2017
One of the main concerns related to tunnel excavations, drilling operations and wellbore stability in shales is the generation of excess pore water pressure due to changes in mechanical stress; therefore the consolidation of shales is a fundamental process that must be considered. This paper presents a compre- hensive methodology for analysing the compression and consolidation behaviour of shales. An apparatus to perform high-pressure oedometric tests is presented and an analytical method is introduced to analyse the shale consolidation behaviour, which allows information to be gathered on the coeffi cient of consolidation, stiffness, poroelastic properties, and permeability of the tested m…
Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 2-Experimental Validation
2012
AbstractAs detailed in Part 1, the most common Italian Technical Specifications refer to different design methodologies for design of lime-soil mixtures, some being quite different from those internationally adopted. Therefore, it seemed appropriate to the Authors to compare these methodologies, via a wide experimental program.It is shown that the Italian methodology of the National Road Agency is different not only from those used in Italy, but also from the main international standards. The experimental results highlight that a revision of that methodology is needed in order to bring it into line with what is prescribed by the European standard.
Advances in Laboratory Testing and Modelling of Soils and Shales (ATMSS).
2017
This volume contains the invited keynote and feature lectures, as well as the papers that have been presented at the workshop. The topics of the lectures and papers cover a wide range of theoretical and experimental research, including unsaturated behaviour of soils and shales, multiphysical testing of geomaterials, hydromechanical behaviour of shales and stiff clays, the geomechanical behaviour of the Opalinus Clay shale, advanced laboratory testing for site characterization and in situ applications, and soil–structure interactions.
The Role of Anisotropy on the Volumetric Behaviour of Opalinus Clay upon Suction Change
2017
An experimental investigation to analyse the anisotropic volumetric response of shaly and sandy facies of Opalinus Clay upon suction variations is presented. Obtained results demonstrate the different behaviour of the tested facies to a wetting-drying cycle. The shaly facies exhibits higher water retention capacity and stronger volumetric response than the sandy facies. Anisotropic response is experienced by both facies with the strain perpendicular to bedding higher than in the parallel direction. The sandy facies exhibits a more pronounced anisotropic behaviour in particular during the drying phase. A detailed analysis of the response in the two directions with respect to the bedding orie…
Circulating markers of retinal and optic nerve lipids
2013
Purpose Blood lipids are frequently used as a surrogate of lipid composition of peripheral tissues. Even if it is well accepted, such a relationship has never been clearly demonstrated for the eye. The aim of this study was to determine in human samples whether a lipidomic approach based on red blood cells could reveal associations between circulating and ocular lipid profiles. Methods Red blood cells, retinas and optic nerves were collected from 9 human donors. The lipidomic analyses on these tissues were done by both, gas chromatography and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS/MS). Results Gas chromatographic approach did not show…
Ether-lipid and docosahexaenoic acid (DHA) levels in erythrocytes of patients with glaucoma
2008
International audience; Purpose: : Neuronal tissues such as the brain and the retina are known to contain elevated amounts of phospholipids with a vinyl-ether double bond (ether-lipids or plasmalogens) as well as high concentrations of long-chain omega-3 polyunsaturated fatty acids (docosahexaenoic acid or DHA). Abnormal blood levels of ether-lipids and DHA have been associated with several neurological disorders such as Alzheimer Disease. Since many observations bring up the idea of pathogenetic similarities between Alzheimer Disease and glaucoma, the aim of our work was to check whether ether-lipid and DHA levels were modified in glaucoma patients. Methods: : Blood samples were collected …
Hemoglobin point-of-care testing: the HemoCue system.
2013
Besides the use of traditional laboratory resources, the diagnosis of anemia can also be accomplished by assessing hemoglobin (Hb) concentration with point-of-care testing (POCT) devices such as the HemoCue test systems. In several situations, these devices might suitably replace traditional laboratory testing, including several areas of health care where a very rapid Hb measurement might be required to make immediate therapeutic decisions. The use of these devices, however, should fulfill some basic criteria, including economic, clinical, and regulatory issues; appropriate training of the users and knowledge of test requirements, performance, limitations, and potential interferences; the u…