Techno Press
You logged in as Techno Press

Geomechanics and Engineering
  Volume 37, Number 2, April25 2024 , pages 109-122
DOI: https://doi.org/10.12989/gae.2024.37.2.109
 


A novel triaxial testing device for unsaturated soils with measurement of suction and volumetric strains
Qian-Feng Gao, Mohamad Jrad, Mahdia Hattab, Said Taïbi and Jean M. Fleureau

 
Abstract
    Standard triaxial cells are commonly used to measure the mechanical behavior of saturated soils. However, this type of standard system is difficult to use for unsaturated soil specimens since it cannot measure the changes in the pore-air volume and pressure. This paper proposes to extend the measurement possibilities of the standard triaxial testing device in a simple way and to adapt it to partially saturated soils. The system is supplied by two hygrometers installed at each end of the cylindrical unsaturated specimen to measure local relative humidity, which allows the derivation of suction. The volumetric strain of the specimen is calculated by analyzing digital photos captured from the outside of the transparent cell wall. Specimens made of kaolin clay, having different hydraulic properties, were tested to verify the reliability of the measurements, and thus, the relevance of the proposed techniques to study the mechanical behavior of unsaturated soils.
 
Key Words
    hygrometer; suction; triaxial test; unsaturated soil; volume change
 
Address
Qian-Feng Gao: School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China;
Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux, Universite de Lorraine – CNRS UMR 7239,
Arts et Metiers ParisTech, Metz, France
Mohamad Jrad and Mahdia Hattab: Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux, Universite de Lorraine – CNRS UMR 7239, Arts et Metiers ParisTech, Metz, France
Said Taïbi: Laboratoire LOMC, Université Le Havre Normandie & CNRS, Le Havre, France
Jean M. Fleureau: Laboratoire de Mécanique de Paris-Saclay, Universite Paris-Saclay, CentraleSupelec, ENS Paris-Saclay,
CNRS UMR 9026, 3 Rue Joliot Curie, 91190 Gif-sur-Yvette, France
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2024 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: info@techno-press.com