A consistent calibration process for the Matsuoka–Nakai friction angle under direct simple shear conditions for clay hypoplasticity. (October 2022)

• Record Type: Journal Article
• Authors: Medicus, Gertraud; Kwa, Katherine A.; Cerfontaine, Benjamin
• Is Part Of: Computers and geotechnics. Volume 150(2022)
• Publication Date: 2022-10
• Subjects: 00-01 -- 99-00; Hypoplasticity -- Matsuoka–Nakai -- Clay -- Direct simple shear -- Critical state; Engineering geology -- Data processing -- Periodicals; Soil mechanics -- Data processing -- Periodicals; Rock mechanics -- Data processing -- Periodicals; 624.1510285
• DOI: 10.1016/j.compgeo.2022.104888
• Languages: English
• ISSNs: 0266-352X

Abstract

Abstract: In geotechnical engineering, direct simple shear (DSS) tests are used to determine strength and stiffness parameters of a material. DSS predictions of a constitutive model influence failure mechanisms in plane-strain, finite-element applications. In this article, we introduce a closed-form solution to determine the Matsuoka–Nakai equivalent critical friction angle from direct simple shear stress and normal stress data. In order to apply it to clay hypoplasticity (Mašín, 2013), we carry out DSS simulations to investigate rotations of principal stresses and the principal stress state at critical state for plane-strain conditions. Finally, we interpret DSS predictions of clay hypoplasticity for different overconsolidation ratios and demonstrate that the location of the CSL in the vertical stress–void ratio plane coincides with the location of the CSL in mean effective stress–void ratio plane.