The Use of Laboratory Indentation Testing to Characterize Champlain Sea Clay
- PDF / 1,292,539 Bytes
- 19 Pages / 547.087 x 737.008 pts Page_size
- 22 Downloads / 150 Views
(0123456789().,-volV) (0123456789().,-volV)
ORIGINAL PAPER
The Use of Laboratory Indentation Testing to Characterize Champlain Sea Clay Mireille Sandrine Ewane . Vincenzo Silvestri . Michael James
Received: 7 August 2017 / Accepted: 28 June 2020 Ó Springer Nature Switzerland AG 2020
Abstract This paper presents a description, the results and analysis of instrumented indentation testing of intact specimens of a Champlain Sea Clay. Five indenters of different geometries and composed of different metals were used. Indentation was conducted to target loads that varied from 2 to 32 N with unloading and force, P, versus penetration, h, curves were recorded. Conventional geotechnical testing was also conducted on the clay. These included index property and characterization testing as well as consolidation, unconfined compression and consolidated undrained triaxial compression. Existing analytical and theoretical solutions were applied to the indentation test results to deduce the hardness, undrained shear strength and Young’s modulus. However, these were found to be not applicable to the clay for a few reasons. An innovative analytical solution that considers the behavior of the clay and the geometry of the indenters is proposed. It was found that a penetration of 4 mm is necessary for the hardness to reach a constant asymptotic value. The
M. S. Ewane (&) V. Silvestri Department of Civil, Geological, and Mining Engineering, Polytechnique Montre´al, P.O. Box 6079, Station Centre–Ville, Montre´al, QC H3C 3A7, Canada e-mail: [email protected] M. James Agnico Eagle Mines Limited, Toronto, ON, Canada
proposed solution was validated using indentation test data. Keywords Indentation tests Champlain sea clay Rigid conical indenters Sensitive clay soil Young’s modulus Hardness Undrained shear strength
1 Introduction Instrumented indentation testing is used widely in material sciences to evaluate the behavior and quantify the properties of various types of materials. Tests can be conducted at nano-, micro- or macro-scales and are reliable, relatively inexpensive and repeatable. Typically, indentation testing consists of the penetration of a specimen of material with an indenter at a constant rate until a given load on the indenter (or depth of penetration) is attained. After a brief pause, the indenter is withdrawn at the same rate until the load (or depth of penetration) returns to zero. In some cases, several cycles of penetration and withdrawal are made at the same location on the specimen to evaluate residual behavior and properties. Instrumentation allows the load on the indenter and the depth of penetration to be recorded continuously during testing (Bolshakov and Pharr 1998; Bucaille et al. 2003; Cheng and Cheng 1998a, b; Dao et al. 2001; Doerner and Nix 1986; Oliver and Pharr 1992; Suresh et al. 1999; Tabor 1951). In geotechnical engineering, a
123
Geotech Geol Eng
very basic form of indentation testing of clay is often conducted using hand-held penetrometers on clay specimens in th
Data Loading...
