Thermal conductivity is a fundamental physical property governing heat transfer in soil. It depends on soil types, pore structure, temperature, and moisture content, can vary over an order of magnitude. Some theories have been established to address the effect temperature thermal conductivity. Other theoretical works focus content different sandy loamy soils. This work addresses all types for ambient temperatures from 20 25°C. varies little within hydration capillary regimes, moderately...

A soil-shrinkage curve (SSC) can be defined as the characteristic volume–water content relation under free external stress conditions. SSC is traditionally divided into three states: normal shrinkage when soil saturated, residual unsaturated and subjected to volume reduction, zero approaches dry state. Using measured SSC, water-retention (SWR) curve, suction of various silty clayey soils, traditional states are found not well incorrect, particularly conceptual model for proposed in which...

The small-strain shear modulus G0 is a property fundamental to the deformation response of soils dynamic loading. It depends on soil mineralogy, particle characteristics, void ratio, effective stress, and degree saturation. Some theories have been established predict under variably saturated conditions. Accordingly, new unified model was developed for different based two conceptual mechanisms: material hardening/softening, which considered using saturation as variable, interparticle contact...

Shear wave propagation in soil is a physical phenomenon and has been used widely for monitoring seismic property assessment geotechnical engineering. velocity Vs small-strain shear modulus G0 are the key parameters defining material response to various dynamic loadings. To date, dependencies of on saturation, especially high suction range, still not well understood because limited testing methodology experimental evidence. In this study, authors present new laboratory instrumentation...

Although siting of thermal energy storage systems in the vadose zone may be beneficial due to low conductivity unsaturated soils, water phase change and vapor diffusion soils surrounding geothermal heat exchangers play important roles both injection retention processes that are not considered established design models for these systems. To better understand roles, this study incorporates recently-developed coupled thermohydraulic constitutive relationships into a transfer flow model...

Drying-induced consolidation in soil is defined as volumetric shrinkage by interparticle stresses (suction stress) during drying under conditions of zero external or total stress. A new analysis presented to synthesize recently published and experimental data for water retention, shrinkage, physicochemical properties, index properties a broad range soils ranging from nonexpansive highly expansive. The suction stress characteristic curves these are computed compared using two...

The small-strain shear modulus G0 is a fundamental property governing wave propagation in soil. It depends on fabric of soil particles, water content, and stress state. dependency content was assessed by using the suction stress-based effective principle. Here variation with compared soil-water retention (SWR) behavior for 12 soils under zero total conditions. A recently established SWR model enables distinction capillary adsorption regimes better interpretation correlation between stress....

Abstract The lowest matric potential is an important soil property characterizing the strength of retaining water molecules and a key parameter in defining complete retention curve. However, exact value still unclear cannot be measured due to limitation current experimental technology. In this study, general theoretical framework based on metadynamics was proposed determine quartz minerals. derived from partial volume free energy can further calculated by difference between adsorption...

Salt-affected soils, including saline and alkali cover about 7% of the land area on earth. Their interaction with water differs from non-saline thereby exhibiting distinct fundamental properties mechanical hydrological behaviors. The soil-water is generally assessed by vapor sorption isotherm, i.e., relationship between soil content ambient relative humidity under isotherm conditions. Yet to date, there still lacks a comprehensive dataset isotherms salt-affected soils. This study presents...

The stress-dependent curve of shear modulus degradation with increasing strain amplitude is a fundamental mechanical property soils. Although it well known that the degree saturation has an important impact on small unsaturated soils, its role evolution not been thoroughly investigated. A testing program revealed strong correlations between two key parameters curve, reference and coefficient curvature, soil water retention (SWRC). An SWRC model capable distinguishing in capillary adsorption...

Abstract The evolution of the liquid‐vapor interface plays a key role in multiphase flow, heat and mass transfer, fluid phase change porous media. In soil water evaporation process, vaporization occurs only on interfaces rather than apparent surface. Yet, evolve with high distortion great complexity along drying path. Hence microscale characteristics especially geometrical topological features are barely investigated. this work, we scanned glass bead samples using X‐ray micro tomography...

Soil desiccation crack is ubiquitous in nature, yet the physics of its initiation and propagation remain under debate, as it involves complex interactions across multiple fields mechanics, hydraulics, thermals. Here, an experimental attempt made to uncover role substrate roughness on soil process. The deliberately fabricated by 3D printing, whereas thickness sample environmental humidity are controlled eliminate effect large hydraulic gradient. Four types soils with varying expansibilities...

The phase equilibrium and mechanical behaviors of natural gas hydrate-bearing sediment are essential for exploiting hydrate reservoirs. In heating closed systems, the temperature-pressure path deviates from that pure bulk hydrate, reflecting porous media effect in equilibrium. A generalized equation was established sediments, which indicates both capillary osmotic pressures cause curve to shift leftward on plane. contrast always contains a certain amount unhydrated water, keeps with within...

Abstract Thermal conductivity of unsaturated soil depends on water content and type. A transient release imbibition method (TRIM) is modified to include measurement the thermal function (TCF) in conjunction with concurrent retention curve (SWRC) hydraulic (HCF). Two pairs dielectric needle sensors are embedded specimen monitor spatial temporal variation content, conductivity, diffusivity during drying wetting processes. Three different soils, including pure sand, silt, clayey sand used...

Abstract Suction stress is the effective independent of mechanical boundary conditions but due to water content variation. It occurs on or near particle contacts and does not directly transfer through soil skeleton hence can only be has been measured indirectly deduced from soil’s strength deformation. In this work, a new technology measure soil-water retention curve, shrinkage suction characteristic curve in high environment established. A humidity-controlled device was developed based...