Generalized stress-path-dependent soil behaviour with a new hollow cylinder torsional apparatus

Abstract

A new hollow cylinder torsional shear apparatus is described. The apparatus is suitable for investigating soil behaviour under generalized stress paths, including principal stress rotations, characteristic of earthquake and offshore-wave loadings. A new, more rational assessment of stress nonuniformity across the wall of the hollow cylinder specimen is made, and the "no go" regions of the stress space are delineated that limit stress nonuniformity to acceptable levels. Operation of the apparatus and experimental procedures for tests on reconstituted specimens of sand are described. Typical results of drained tests on loose and dense sand are presented to illustrate the capabilities of the apparatus as a general stress-path loading device and to highlight the stress-path dependence of soil behaviour, in particular, the deformation response to principal stress rotations. Key words: hollow cylinder apparatus, generalized stress paths, principal stress rotation, sand, deformations.

Experimental investigation on the deformation characteristics of granular materials under drained rotational shear

“…Oda et al 1978;Tatsuoka et al 1990, Alshibli andSture 2000;Wanatowski and Chu 2006), directional shear cells (Phillips and May 1967;Oda and Konishi 1974a, b;Wong and Arthur 1985), true triaxial apparatuses (Arthur and Menzies 1972;Yamada and Ishihara 1979;Ochiai and Lade 1983;Miura and Toki 1984;Abelev and Lade 2004) and hollow cylinder apparatuses (e.g., Symes et al 1988;Miura and Toki 1986;Vaid et al 1990;Gutierrez et al 1991;Nakata et al 1998;Rolo 2003;Lade et al 2008;Cai et al 2013). …”

Modeling principal stress rotation for anisotropic sand

“…1) has been commonly used to investigate the effects of principal stress rotation during shear of sand (Hight et al 1983;Miura et al 1986;Symes et al 1984; Symes et al 1988;Vaid et al 1990;Tong et al 2010). The four stress components, i.e.…”

Engineering Properties of Wet-Pluviated Hollow Cylindrical Specimens

“…The 2.4 kPa surcharge provided by the self-weight of the top loading platen produced a specimen of uniform density (Vaid et al 1990). The reduction in the specimen height was monitored during densification by recording to 0.01 mm the downward movement of the top loading platen using a dial gauge.…”

“…More elaborate specimen preparation apparatus, which require both inner and outer specimen moulds, are necessary to form the hollow cylindrical sand specimens. Existing apparatus that employed the wet-pluviation technique included those reported by Ishihara and Yasuda (1975), Porovic (1995) and Vaid et al (1990). Specimen boundary effects are also greater for hollow cylindrical specimens than for solid cylindrical specimens since rubber membranes are required to enclose both the inner and outer walls of the specimen.…”

“…A wet-pluviation preparation method was perfected for sand specimens of these dimensions and the initial properties of these specimens were studied. While wet-pluviation techniques have been used by other researchers to prepare hollow cylindrical specimens, the new apparatus had different specimens dimensions, for example Vaid et al (1990) used specimens 152 mm outer diameter, 102 mm inner diameter and 302 mm high, and it was necessary to study the repeatability of the new test method and assess the significance of procedural errors on the constitutive response. The specimen preparation apparatus is described and the effects of the pluviation rate and the level of specimen densification on the repeatability and initial characteristics of the sand specimens quantified.…”