Abstract The freezing temperature of soil is an important index to judge whether it in a frozen state or not, and plays key role distinguishing salt expansion from frost heave. Freezing experiments on sulfate saline its ion solution indicate that the initial mainly determined by properties solution. effects types concentrations are also investigated. An equation calculate deduced Pitzer model validity verified experimental results. Under assumption corresponding energy ice‐liquid interface,...

In this study, a series of freezing experiments were carried out to investigate the changes volumetric unfrozen water contents in soils. The experimental results show that soil type and initial content have significant effect on point On base previous researches, new model was developed describe validated by comparing calculated against ones.

Salt content has been proven to be an important influencing factor on the mechanical properties of frozen saline soils, whose strength criterion is different from that unfrozen soils or without salts. In this paper, a series conventional triaxial tests are carried out for with sodium sulfate at temperature –6 °C. A including influence salt content, established by using generalized nonlinear theory. Based test results, modified hydrostatic pressure expression proposed according critical...

The soil freezing-thawing characteristic curve (FTCC) can reflect the physical and mechanical properties of soil–water system during (FT) process, which is guiding significance to study moisture, heat matter transport in cold regions. In this study, firstly, according evolution law hysteresis with revealing mechanisms at different stages based on ice-water transformation theory. be divided into four as temperature decreasing. first three are due nucleation electrolyte effects, capillarity...

Over 50% of the global land area suffers cyclic freeze-thaw actions, resulting in extensive distribution frozen soil. Frozen soil contains lenses ice, and thus, it exhibits temperature-related properties behaviors. The thermal conductivity is a key property an essential parameter for performing analyses on However, variable cannot be determined accurately based small-scale specimen tests because no specimens are identical nature. Thus, little known about variability statistical...

Abstract An indirect method is nowadays considered as an efficient way to obtain soil‐water characteristic curve (SWCC) in engineering application. However, existing models often oversimplify the soil pore and accumulation structure, which are not consistent with natural soil. For this purpose, a novel granular packing state obtained based on relative compaction determined by porosity. A conceptual SWCC model (WANG24) then established particle size distribution (PSD) equivalent packing. 62...

Polyacrylamide (PAM) is a water-soluble polymer with the ability to enhance soil's stability. PAM currently being used prevent irrigation-induced erosion and infiltration in farmland soil. To improve compaction properties of saline-soil-based filling material that highway subgrade cracking resistance capacity saline crust, consistency limits, compactability, microstructure, morphology untreated PAM-treated soil were investigated. The soils sampled from crust depth 2.0⁻3.0 m Gansu Province,...

Abstract Knowledge of freezing characteristic a porous media is necessary to investigate heat and water transfers in cold regions. The unfrozen content soil‐water system affected by its complicated internal characteristics external factors such as temperature pressure. Although various experimental analytical methods have been proposed explore the complex relation between temperature, most them are empirical or limited. In this study, sphere‐cylinder dual structure according surface...

Abstract The clarification of freezing in a soil‐water system is critical for assessing the formation zone and liquid water flow. supercooling phenomenon soil pore solutions has been found during process, but mechanism remains poorly understood. In this study, we propose free energy function systems based on Classical Nucleation Theory. analytical solution nucleation problem saline obtained by combining initial temperature model Pitzer activity coefficients electrolyte solutions. Then,...

Particle size distribution (PSD) is a rich source of information about soil properties, including gradation and particle characteristics. This paper compared the PSD prediction ability three types mathematical model. We selected nine models that have been proven to accurately predict sample points in previous studies, we fit 144 pieces experimental data on 12 texture classes samples from UNSODA database. models’ capability for predicting non-sample points, which important Each model’s...

The thermomechanical behavior of coal and sandstone during excavation using the freezing method is a new challenge for mining geotechnical engineering. In this paper, influence temperature on mechanical characteristics fracture patterns two types saturated rocks (coal sandstone) were investigated. A series laboratory tests, including Brazilian tensile strength (BTS), uniaxial compressive (UCS), triaxial (TCS), conducted at temperatures 20, -4, -10, -15 °C. results indicated significant...

Abstract In frozen soils, a portion of pore water remains unfrozen due to the effects capillarity, adsorption, and possibly solute. The variation amount ice in soil, which is primarily influenced by subzero temperature, has great impacts on physical mechanical behavior soil critical for broad applications ranging from engineering climate change. present study, various methods that have been used determining (and ice) content are comprehensively reviewed. Their principles, assumptions,...

It has been proven that the mechanical properties of frozen saline soils are different from and unfrozen soils. In this paper, in order to study effects salt contents on strength characteristics soils, a series conventional triaxial compression tests carried out for silty clay with Na 2 SO 4 0.0, 0.5, 1.5, 2.5% under confining pressures 0 MPa 18 at −6°C, respectively. The experimental results show presents obvious nonlinearity, increases increasing first, but further increase pressures,...

Blown sand hazards at the Jieqiong section of Lhasa–Shigatse railway are severe, and their formation mechanism is unclear. Moreover, prevention control work cannot be carried out. Therefore, dynamic blown Railway was investigated by field observation, laboratory analysis, calculation. Results show that yearly sand–moving wind commonly originates from SW direction. The resultant drift direction angle maximum possible transport quantity NE between trend 5°–30°. During dry season, materials up...

Abstract Determining the minimum supercooling temperature ( T sc ) of unsaturated saline soils is key scientific problem in cold‐region agricultural and engineering, theoretical models with good predictability are urgently needed. This study establishes a framework for pore solution freezing nucleation soils, chemical potential energy balance equation was established by determining phase transition driving force barrier formation stable crystal embryos. Finally, physical model constructed....