Volume change characteristics of fine-grained soils due to sequential thermo-mechanical stresses

Abstract

Know-how of volume change characteristics, VCC, of the fine-grained soils, exposed to thermal stresses, is essential for design of various thermo-active structures. These stresses are known to induce excess pore-water pressure, Δu θ , in the saturated state of such soils, which in turn affects their compression and shear strength characteristics. In this context, through several experimental studies, the effect of thermo-mechanical stresspath, the over-consolidation ratio (OCR) and degree of saturation on VCC (viz., thermally induced volumetric strain, ε vθ , compression and re-compression indices, c c and c r) of the fine-grained soils has been demonstrated by earlier researchers. However, the response of these soils when exposed to sequential thermal and mechanical stresses, STMS, due to temperature fluctuation and continued infrastructure development, on VCC has seldom been studied. This motivated us to investigate the VCC of the fine-grained soils, by subjecting them to STMS in a suitably modified oedometer setup which facilitates temperature controlled tests. From the results of STMS tests, it is seen that the ε vθ of these soils exposed to thermal cycles (20-60-20°C) is independent of the thermal stress history experienced at different applied vertical stress, σ v , (= 60, 125, 250 kPa). Furthermore, from the analysis of deformation-time curve of the thermal loading phase, a methodology for direct determination of the volume change component of fine-grained soils, due to structural rearrangement, ΔV sθ , has been proposed. The methodology enables direct computation of the coefficient of volume change due to structural rearrangement, α sθ , that would aid in direct prediction of Δu θ from the deformation-time curve of thermal loading phase.

A thermomechanical model for argillaceous hard soils - weak rocks: application to THM simulation of deep excavations in claystone

“…In general, heating saturated clays, under drained conditions, induces strength and volume changes that depend on the stress history. Temperature-induced volume changes tend to be contractive and irreversible for normally consolidated clays whereas expansive and reversible deformations occur for highly overconsolidated clays (Campanella and Mitchell, 1968;Plum and Esrig, 1969;Baldi et al, 1988;Hueckel and Borsetto, 1990;Sultan et al, 2002;Cekerevac and Laloui, 2004;Abuel-Naga et al, 2006;Tsutsumi and Tanaka, 2012;Di Donna and Laloui, 2015;Shetty et al, 2019). However, experimental data on the thermomechanical behaviour of argillaceous rocks are scarce in the scientific literature (Zhang et al, 2007;Monfared et al, 2012;Zhang et al, 2014;Menaceur et al, 2015;Liu et al, 2019).…”

A thermomechanical model for argillaceous hard soils–weak rocks: application to THM simulation of deep excavations in claystone

“…In general, heating saturated clays, under drained conditions, induces strength and volume changes that depend on the stress history. Temperature-induced volume changes tend to be contractive and irreversible for normally consolidated clays whereas expansive and reversible deformations occur for highly overconsolidated clays (Campanella and Mitchell, 1968;Plum and Esrig, 1969;Baldi et al, 1988;Hueckel and Borsetto, 1990;Sultan et al, 2002;Cekerevac and Laloui, 2004;Abuel-Naga et al, 2006;Tsutsumi and Tanaka, 2012;Di Donna and Laloui, 2015;Shetty et al, 2019). However, experimental data on the thermomechanical behaviour of argillaceous rocks are scarce in the scientific literature (Zhang et al, 2007;Monfared et al, 2012;Zhang et al, 2014;Menaceur et al, 2015;Liu et al, 2019).…”

State parameter–based thermomechanical constitutive model for saturated fine-grained soils

“…After the pioneering work by Campanella and Mitchell (1968), extensive experimental investigations on the thermomechanical behaviour of soils, particularly water-saturated clays, have been conducted (e.g., Abuel-Naga et al 2007b;Baldi et al 1991;Cekerevac and Laloui 2004;Ghahremannejad 2003;Hueckel and Baldi 1990;Kuntiwattanakul et al 1995;Ng et al 2019;Shetty et al 2019;Sultan et al 2002;Tanaka et al 1997;Towhata et al 1993;Uchaipichat and Khalili 2009). It was shown that temperature strongly affects the behaviour of fine-grained soils mainly through its influences on the soil structure and the free and absorbed water.…”