Hydro-mechanical behavior of unsaturated soil surrounding a heated pipeline considering moisture evaporation and condensation

The Impact of Microwave Drying on the Structure of Exemplary Soils—Insights Using X-ray Microtomography

“…Hence, microwaves have a greater impact on specimens with higher water content (as well as lower permeability). This observation corresponded to results of tests by [ 1 ], who noted the possibility of remarkable sensitivity of the thermo-hydro-mechanical response to a change in temperature in “unsaturated clay, while this observation is absent in soils whose permeability is greater than that of silty sand”. In this way, the microwaves penetrate the interior of the material, heating up the entire volume from the inside.…”

“… Sand microwave drying: perpendicular microtomographic sections through the medium sand sample after microwave drying ( a ); schematic of unsaturated soil illustrating moisture evaporation and condensation modified from [ 1 ] ( b ). …”

“…Different soil drying methods can have various effects on the structure and, thus, on the geomechanical and filtration features (thermally induced thermo-hydro-mechanical behavior of saturated or unsaturated soils [ 1 , 2 , 3 ]). The rapid change in conditions can affects the soil fabric [ 4 ] and therefore, it can weaken the soil grains or solid material, leading to cracking, fracturing, and crushing.…”

Modelling the thermal–hydro-mechanical behaviour of unsaturated soils with a high degree of saturation using an extended precise integration method

“…When temperature rises, the bubbles expand and both the processes of seepage and deformation are influenced accordingly, which can strongly affect the engineering characteristics of soils and make the hydro-mechanical coupling processes much more complicated. However, little research evidence on thermal-hydro-mechanical (THM) coupling behaviour of HDS soils is available, although the temperature influence on the hydro-mechanical behaviour and characteristics of bubbles in GWM has been highlighted in previous investigations (Sills et al 1991;Fredlund and Rahardjo 1993;Sultan et al 2012;Selvadurai and Najari 2017;Zhu et al 2020). A number of relevant works have focused on the THM behaviour of saturated soils (Sultan et al 2002;Cui et al 2009;Selvadurai and Suvorov 2014;Ai and Wang, 2016) or unsaturated soils with continuous gas phase (Thomas et al 2009;Zhu et al 2020).…”

“…However, little research evidence on thermal-hydro-mechanical (THM) coupling behaviour of HDS soils is available, although the temperature influence on the hydro-mechanical behaviour and characteristics of bubbles in GWM has been highlighted in previous investigations (Sills et al 1991;Fredlund and Rahardjo 1993;Sultan et al 2012;Selvadurai and Najari 2017;Zhu et al 2020). A number of relevant works have focused on the THM behaviour of saturated soils (Sultan et al 2002;Cui et al 2009;Selvadurai and Suvorov 2014;Ai and Wang, 2016) or unsaturated soils with continuous gas phase (Thomas et al 2009;Zhu et al 2020). Apart from a limited number of studies (Selvadurai and Najari 2017;Wang and Ai 2018) discussing the influence of pore fluid compressibility on THM responses, no research effort has been directed to explore the coupling effects of S r , temperature and thermal expansion characteristics of soil grains on the behaviour of the HDS soils.…”