Sediment shear strength. Using the laboratory T-bar and effect of the diameter

Daniel LEVACHER, Andry RAZAKAMANANTSOA, Ritesh GUPTA

Résumé


Dehydration of the dredged sediments is necessary in different operations of sediment valorization: lagunage, handling and transport of sediments. The evaluation of hydric properties (WC water content, LL liquidity limit, PL plastic limit, SL shrinkage limit) and of undrained shear strength Su must be made to ensure the follow-up of these operations (slopes stability, reversal of wind-rows in lagunage basins, bearing capacity of engines circulating on layers of sediments, consistency of the sediments, effect of remolding under cyclic request,…), rate of dehydration or drying. In first approach, the relation Su–WC could answer the problems posed. Measurement of the water content WC can be given by sampling; these samples obtained which also make it possible to follow the evolution of the components of the sediments (environmental properties, OMC organic matter content, pollutants level). For measurement of undrained shear strength, two laboratory tools are transposable on site: Vane Shear Test (VST) and the T-Bar Test (TBT). The first provides discrete measurements of Su, the second, continuous measurements. This last is sometimes used in laboratory. TBT Test can be used in vertical alternate cycles (penetration-extraction) and record the degradation of undrained strength. This tool allows the establishment of the relation Su–WC. Once presented the T-Bar Test geometry, kaolin clay properties and experimental set-up are given. Some geometry influences, (diameter, proximity, roughness) are commented.


Mots-clés


T-bar test, Kaolin clay; Undrained shear strength; Scale effect; Laboratory testing.

Texte intégral :

PDF (English)

Références


BOUSSAID K. (2005). Sols intermédiaires pour la modélisation physique: application aux fondations superficielles. Thèse de doctorat, Ecole Centrale de Nantes, Université de Nantes, 287 p.

CHERIFI E. (2013). T-bar laboratory testing on reconstituted clay. Master report, Caen University, 65 p.

HOUSE A.R., OLIVEIRA J.R.M., RANDOLPH M.F. (2001). Evaluating the coefficient of consolidation using penetration tests. International Journal of Physical Modelling in Geotechnics, Vol. 1(3), pp 17-26. CrossRef

LEVACHER D., RAZAKAMANANTSOA A., KIMURA F., KATSUMI T. (2014). Use of sedi-bar test for the characterization of soft soils and sediments. Geo-Environmental Engineering, GEE 2014, Sapporo, Japan, May 30–31, pp 8-15.

OROZCO-CALDERON M., FORAY P., PUECH A., HALL S. (2010). Essais au mini-Tbar à faible pénétration. Journées Nationales de Géotechnique et de Géologie de l’Ingénieur JNGG2010, Grenoble, pp 135-142.

STEWART D.P., RANDOLPH M.F. (1994). T-bar penetration testing in soft clay. Journal of Geotechnical Engineering, Vol. 120, pp 2230-2235. CrossRef

YAFRATE N.J., DE JONG J.T., DE GROOT D.J. (2007). The influence of full-flow penetrometer area ratio on penetration resistance and undrained and remoulded shear strength. Offshore Site Investigation and Geotechnics, Confronting New Challenges and Sharing Knowledge, London, pp 461-468.




DOI: http://dx.doi.org/10.5150/revue-paralia.2016.s01

Renvois

  • Il n'y a présentement aucun renvoi.


 

_ISSN 1760-8716_

© Editions Paralia CFL