This article presents the development, calibration, and performance of a triaxial cell developed to study thermomechanical behavior soils under controlled heating cooling rates sinusoidal temperature changes mimicking real field conditions. uses bipolar thermo-electrical devices fully control applied thermal loads. The can accommodate specimens up 75 mm in diameter with height-to-diameter ratio 2 2.5. Tested soil be subjected temperatures ranging from −5°C 70°C specimen change rate...

Abstract This article presents a thermomechanical triaxial cell modified to fit inside synchrotron X-ray diffraction (XRD) beamline aiming assess thermally induced microstructural changes in saturated clays under situ conditions. Understanding these alternations will explain some of the poorly understood or misunderstood concepts about behavior soils; this, turn, allow more robust designs geostructures for thermal and energy applications. Compared other techniques, provides (1) high accuracy...

The goal of this paper is to present the effect heating and cooling thermal loads on load-displacement response heat exchanger piles in granular soils. Two-dimensional discrete element simulations were utilized determine changes shaft toe resistances due loads. considered pile 0.3 m diameter 20 length it was installed a homogeneous sand layer with particles ranging size between 2.2 3.6 mm. divided into 5 segments representative 0.5 strip for each segment. For modeled element, vertical...

This paper presents the preliminary results for use of filler-stabilized biopolymers to enhance mechanical properties sands. Biopolymers include natural polymers produced by micro-organisms or artificially manufactured fully degradable polymers. Several studies in literature have reported successful (e.g. xanthan gum, agar guar gum) as additives soil improvements. However, concerns were also raised about strength dependency these improved soils on moisture content well expected increase...

A discrete numerical model developed for cohesive soils was utilized to study the thermo-mechanical behavior of a saturated kaolinite. The physico-chemical interactions that exist between clay particles, mainly van der Waal attractive and double layer repulsive forces, were considered. Van interaction modelled based on hybrid Hamaker-de Boer-Lifshitz approach. Further, Gouy-Chapman theory. brief discerption implementation in element framework is presented. Moreover, effect temperature...

This study aims to investigate the effect of various types biopolymers, including xanthan gum (XG), guar (GG), and agar (AG), on shear strength granular media. The environmental impacts using traditional materials, such as cement lime, for soil improvement have led geotechnical engineers consider eco-friendly alternatives. Biopolymers, due their low cost abundance, become an attractive alternative improvement. In this study, biopolymers were introduced at a dry mass ratio 1%. Consolidated...

A discrete element model developed for cohesive soils is utilized to simulate the behavior of saturated clays subjected drained shearing. The platy-shaped clay particles are modelled, and physico-chemical forces exist in assemblies considered. numerical specimen preparation mimics physical prior shearing, where a kaolin slurry was one-dimensionally consolidated target 1D effective stress, then isotopically-consolidated at 20°C temperature-controlled triaxial cell isotropic stress. sheared...

This paper explains the thermally induced volume changes in saturated normally consolidated clays using microscale changes. To achieve this goal, a discrete element model accounting for physico-chemical interactions between clay particles (i.e., van der Waals attractive and double layer repulsive forces) was employed study. The developed first validated against thermo-mechanical experimental results then it used to assess microstructural evolution of interparticle forces separation distances...

The aim of this study is to assess the potential encountering a heating-induced creep rapture clay liners in nuclear waste repository. Groundwater and soil contaminations may occur if elevated temperatures, expected vicinity repository, trigger liners. In study, we utilize simulations based on discrete element method (DEM) understand conditions under which rupture can take place. lieu conventional local/non-local damping mechanism usually utilized DEM dissipate energy, presented incorporate...

At the same effective stress, shear strength of consolidated clays is a function stress history. Normally clay specimens tend to contract upon shearing while overconsolidated dilate. Moreover, have peak normally plateau their critical state. In this study, two-dimensional (2D) discrete element method (DEM) simulations for kaolinite at different histories are presented. Clay particles modelled as rigid rods (clumps) in framework, with sizes replicating actual particle size distribution used...

This paper reviews the application of magnetic resonance imaging (MRI) for monitoring pore water in different porous media. The physics MRI and techniques are first presented detail, studies focusing on quantifying flow media reviewed. Then, we present results scans a poorly graded sand (badger sand), scanned utilizing 9.4 Tesla scanner. specimen was saturated with deionized (DI) PVC container, then placed inside (MR) scanner fast low angle shot (FLASH) sequence imaging. collected 2D images...

The goal of this study is to reveal the multiscale mechanism soils undergo during heating retained backfill. Free-drainage surrounding energy piles or behind thermo-active tunnels retaining walls experience heating/cooling due heat exchange with ground. Soils, therefore, expand/contract, rotate, displace, and change its stress state, which results in changing lateral earth pressure experienced by piles/walls. To particulate such state change, a two-dimensional (2D) discrete element model...

The overall goal of this study is to reveal the microscopic phenomena governing fabric impacts on shear strength and stiffness clays using two-dimensional (2D) discrete element models (DEM). Experimental evidence suggests that clay (i.e., arrangements particles void spaces) strength. Under a given effective stress, normally consolidated with dispersed have higher strengths stiffnesses than those flocculated fabrics. 2D DEM reported here consider short- long-range interparticle forces between...