Search Results (316)

The stability of engineering structures in frozen regions is primarily governed by the coupled evolution of temperature, moisture migration, and stress fields driven by freeze–thaw cycles. In this study, a typical embankment section in Heilongjiang Province, a seasonally frozen region of China, is selected as a case study. To investigate the influence of river operating water levels on the spatiotemporal evolution of temperature and deformation fields in freeze–thaw cycles, this study establishes a thermo-hydro-mechanical (THM) numerical analysis framework through Python 3.8.10.-based ABAQUS secondary development. A representative annual ground-surface temperature boundary derived from ERA5-Land reanalysis data is adopted as the continuous thermal boundary condition. Two middle-drainage water states, namely water-filled drainage and water-free drainage, are considered. Design and check water levels are applied to evaluate the evolution of the temperature field, freezing depth, and deformation in freeze–thaw cycles for the embankment section soil. The predicted temperatures show seasonal trends consistent with ERA5-Land soil-temperature reanalysis data at depths of 0, 25, and 50 cm. The maximum freezing depth at the representative location on the left slope is 1.66 m, which falls within the field-measured freezing-depth range of 1.5–2.0 m. These comparisons indicate that the temperature-field and freezing-depth simulations are reasonable. Under all operating conditions, soil deformation accumulates with freeze–thaw cycles and shows a stabilization trend characterized by rapid early growth and small later increments. After the ninth cycle, the maximum deformations under the water-filled/design-level, water-filled/check-level, water-free/design-level, and water-free/check-level conditions are 15.49, 15.95, 17.81, and 18.48 mm, respectively; these values are far smaller than the reserved settlement allowance of 18 cm. Compared with the water-filled case, the deformation for the water-free case increases by approximately 15.0% under the design water level and 15.9% under the check water level. The results indicate that the condition of water-filled drainage is a dominant factor in freeze–thaw deformation, and water level fluctuation is another influencing factor. Full article

Loess mountainous regions in northern China suffer frequent landslides, collapses and debris flows controlled by complex geological settings, seasonal rainstorms, freeze–thaw cycles and large-scale human engineering activities. Multi-geohazard susceptibility evaluation can provide fundamental data support for regional disaster prevention and territorial planning. Taking Shanxi Province, a typical loess-mountain transition zone, as the study area, this paper establishes an evaluation framework for landslides, collapses and debris flows. Ten conditioning factors are selected, including lithology, terrain parameters, distance to faults, distance to rivers, NDVI and RX1day (annual maximum 1-day precipitation). A 30 m grid unit is adopted as the basic evaluation unit. A total of 2598 verified geohazard points are taken as positive samples. Negative samples with equal quantity are extracted from low and very low susceptibility areas of the preliminary zoning map generated by the Frequency Ratio (FR) method, with an 800 m minimum separation distance between sampling points to reduce spatial autocorrelation. Two models, Logistic Regression (LR) and Support Vector Machine (SVM), are constructed, and five-fold cross-validation is used to test model performance through five statistical indicators and AUC values. The results show that, under the specific model configurations and sampling strategy adopted in this study, the LR model achieved higher predictive performance (average test AUC = 0.995) than the SVM model (average test AUC = 0.752) in the comparative assessment. Statistical analysis of the final susceptibility map derived from the LR model indicates that high and very high susceptibility zones account for 80.94% of the total provincial area and contain 87.45% of all recorded geohazard points, which confirms the consistency and reasonableness of the zoning results. Spatially, high-susceptibility areas are concentrated in the western and northwestern loess tablelands, the Fenhe River fault basin, and fault-developed sections of the Lüliang and Taihang Mountains. Thick loess layers, river undercutting and coal mining activities jointly reduce slope stability in these zones. Compared with conventional susceptibility modeling workflows, this study incorporates the RX1day extreme precipitation index and implements Frequency-Ratio-constrained stratified negative-sample selection to reduce training-sample bias. The produced susceptibility maps can provide technical support for differentiated geological hazard risk management, ecological restoration and territorial spatial planning for loess-mountain transition regions in northern China, thereby directly contributing to regional sustainable development and disaster resilience. Full article

Freeze–thaw cycling can alter soil–structure interface response in seasonally frozen regions. This study investigated the direct-shear behavior of a commercially sourced silty-loam–concrete interface subjected to sealed freeze–thaw cycling. A 25-condition mixed-level design based on the standard L25(5⁶) orthogonal array (25 runs with six available five-level columns) considered normal stress, nominal interface roughness, moisture content, and freeze–thaw-cycle number; each main condition was tested once, so the results are interpreted descriptively. Shear strength and shear-induced vertical contraction were measured, and digital image correlation (DIC) was used to characterize surface deformation localization. The level-wise mean shear strength increased with normal stress and approximately linearly with roughness. It changed little between 14% and 18% moisture content and decreased at 22% and 26%; the measured plastic limit was 19.2%. With increasing freeze–thaw cycles, the level-wise mean strength decreased to three cycles, then recovered and approached stabilization. These results provide laboratory-scale evidence under the tested closed-system conditions rather than directly transferable pile-design parameters. Full article

Continuous monitoring of permafrost dynamics remains challenging in remote high-mountain environments due to logistical constraints, harsh climatic conditions, and the limited availability of spatially distributed observations. In addition to direct temperature observations in boreholes, Autonomous Electrical Resistivity Tomography (A-ERT) offers significant potential for long-term monitoring by providing high temporal resolution observations of subsurface electrical properties, which are highly sensitive to freeze/thaw processes. This study presents the field validation of a low-power A-ERT system designed for long-term autonomous operation in extreme environments. The system was deployed at a high-altitude permafrost site near the Kumtor gold mine in the Central Tien Shan, Kyrgyzstan, representing the first application of continuous A-ERT monitoring in the Central Asian mountain ranges. The system operated continuously under harsh environmental conditions with air temperatures as low as −30 °C. Data quality remained consistently high throughout the monitoring period, with less than 1% of measurements removed during filtering, and inversion results with root-mean-square errors generally ranging between 3% and 4%. Time-lapse resistivity observations revealed strong seasonal freeze–thaw dynamics within the active layer and continued seasonal resistivity variations within the underlying permafrost despite permanently frozen conditions. Analysis of depth-dependent resistivity–temperature relationships revealed increasingly pronounced hysteresis behavior below the active layer, indicating that subsurface electrical properties were not controlled solely by temperature. This behavior likely reflects variations in unfrozen water content and pore connectivity within the fine-grained permafrost, where liquid water can persist at sub-zero temperatures. The results demonstrate the capability of the A-ERT system for reliable long-term autonomous monitoring in remote permafrost environments and investigation of coupled thermal and hydrological processes in permafrost systems. Full article

Dispersive soils are widely distributed in the seasonally frozen regions of northeastern China, where hydrothermal dynamics driven by seasonal freeze–thaw (FT) cycles dominate the hydrological evolution and mechanical deterioration of soil masses, posing a serious threat to the long-term stability of hydraulic engineering in cold regions. However, the hydro–thermo–mechanical (HTM) coupled degradation mechanisms of dispersive clay from the South Nenjiang Main Canal remain poorly understood, particularly the linkage between FT-induced microstructural evolution and macroscopic mechanical behavior. In this study, low-plasticity dispersive clay specimens were subjected to 0–12 FT cycles. Unconsolidated undrained (UU) triaxial tests were conducted to evaluate mechanical behavior, while scanning electron microscopy (SEM) combined with the Pore and Crack Analysis System (PCAS) was used to quantify microstructural evolution. Results indicated that increasing FT cycles transformed the stress–strain response from mild strain-softening to strain-hardening, with the failure mode evolving toward bulging-type ductile failure. Cohesion exhibited a pronounced exponential decay, with the most significant degradation occurring within the first three FT cycles and stabilizing after approximately six FT cycles, whereas the internal friction angle showed only minor variation. At the microscale, porosity and total pore area increased continuously through micropore coalescence and macropore development, with a slight decrease in fractal dimension indicating reduced pore boundary complexity and smoothed pore interfaces due to frost heave-induced pore merging. The FT-induced hydrothermal disturbance promoted pore-water phase transition and redistribution, resulting in progressive pore enlargement and loss of structural integrity. Because the specimens were tested in sealed, closed-system conditions with a nearly constant total water content, this degradation chain is attributable specifically to in situ ice–water phase transitions and internal pore-water redistribution, i.e., water-phase-change-driven processes, rather than to external water supply. It is demonstrated that interparticle bond breakage and pore expansion–coalescence driven by ice–water phase transitions dominate strength degradation, promoting a transition from structure-dominated to friction-dominated strength behavior. A normalized cohesion reduction factor and a cohesion degradation index are further proposed to quantify the progressive loss of structural integrity and to provide a design-oriented tool for cold-region geotechnical practice. These findings provide a basis for stability assessment and hazard mitigation of dispersive soils in cold-region engineering. Full article

Cold recycled mixtures with bitumen emulsion (CRME) serving in seasonally frozen regions are susceptible to mechanical deterioration under repeated freeze-thaw (F-T) cycles, which is primarily manifested as interfacial damage and crack propagation. However, the micro-mechanical processes associated with the transmission and dissipation of frost-heaving stresses induced by water-ice phase transition within the interfacial transition zone (ITZ) between reclaimed asphalt pavement (RAP) and asphalt mortar remain to be further characterized. In this study, a numerical simulation approach coupling frost heave effects with the phase transition of water-ice particles was developed based on X-ray computed tomography (CT) and the discrete element method (DEM), and the micro-mechanical parameters of the RAP-asphalt mortar ITZ were determined through laboratory experiments. Combined with acoustic emission (AE) monitoring, the damage evolution characteristics of cold recycled mixtures and the associated interfacial damage mechanisms under freeze-thaw action were systematically investigated. The results indicate that the optimal micro-parameters of the RAP-asphalt mortar ITZ can be taken as approximately 85% of those of virgin asphalt mortar. After 20 freeze-thaw cycles, the number of shear cracks and tensile cracks in ITZ on RAP surface reached 493 and 92, respectively, which were much higher than 11 and five on the surface of new aggregate. ITZ was the main control weak area of freeze-thaw damage. Compared with the unfrozen specimens, the minimum effective contact number of mortar decreased by 1.63%, 4.52% and 8.52% respectively after 5, 10 and 20 freeze-thaw cycles, and the total effective contact number decreased from 75,842 to 69,383. Freeze-thaw cycles significantly reduce the strain energy storage capacity of CRME: the maximum energy storage capacity of the adhesive spring decreased from 2.15 J in the non-freeze-thaw state to 1.28 J in 10 cycles (a decrease of 40.47%) and 1.16 J in 20 cycles (a decrease of 46.05%), and the damage mode changed from brittle fracture to interface-controlled energy dissipation. The proposed water-ice phase transition-based DEM framework provides a reliable numerical tool for investigating freeze-thaw damage mechanisms and supporting durability-oriented design of cold recycled pavement materials. Full article

Seasonal freeze–thaw processes affect soil hydrothermal conditions in high-altitude valleys, yet evaluations based only on air temperature or maximum freezing depth may overlook the distinction between surface-connected freezing and delayed thawing within the soil profile. Meteorological conditions, ground surface temperature (GST), ground-temperature profiles, freezing depth, and volumetric water content (VWC) were continuously monitored in an arid valley on the Qinghai–Tibet Plateau. Mean annual GST was 3.23 °C higher than mean annual air temperature, and the freezing and thawing n-factors were 0.72 and 1.54, respectively, indicating weakened cold accumulation and enhanced heat accumulation at the ground surface. The maximum surface-connected freezing depth reached 3.30 m, whereas ground temperatures at 3.5 m and below remained above 0 °C. During spring thawing, a residual frozen layer persisted for 49 days after the shallow layer had thawed, with a maximum thickness of 3.24 m. GST-based freezing degree days represented freezing depth better than air-temperature-based freezing degree days. Soil VWC remained low, and precipitation responses were mainly confined to 0.2 m depth. These findings reveal a thermally dominated freeze–thaw regime with weak deep moisture response and show that distinguishing surface-connected freezing from residual frozen layers improves hydrothermal-state identification in low-water-content sandy gravel deposits. Full article

Freeze–thaw cycling can strongly disturb the pore-water environment, soil fabric, and contaminant mobility of heavy-metal-contaminated loess, thereby threatening the long-term effectiveness of stabilization treatments in seasonally frozen regions. This study investigated the coupled hydro-environmental and geotechnical performance of Pb-contaminated loess (untreated control group, CK) treated with microbially induced calcium carbonate precipitation (MICP), graphene (GR)-assisted MICP, and graphene oxide (GO)-assisted MICP under controlled freeze–thaw cycles. One-dimensional consolidation tests, toxicity characteristic leaching procedure (TCLP) tests, zeta-potential measurements, X-ray fluorescence (XRF), and scanning electron microscopy (SEM) were conducted to evaluate compressibility evolution, Pb leaching behavior, interfacial electrochemical characteristics, mineralogical changes, and microstructural mechanisms. After 9 days of mineralization, MICP reduced the Pb leaching concentration from 38.05 to 23.00 mg L⁻¹, achieving a 39.55% reduction compared with untreated Pb-contaminated loess. Freeze–thaw cycling increased the susceptibility of treated loess to structural degradation and pore collapse, especially under medium to high vertical stresses. Nevertheless, the void ratio generally followed the order of CK > MICP > MICP + GR > MICP + GO under comparable loading and freeze–thaw conditions, indicating progressively enhanced resistance to compressive deformation. GR-assisted MICP showed an optimum dosage of approximately 1.0%, beyond which Pb leaching increased because of sheet restacking, agglomeration, and non-uniform biomineralization. In contrast, under up to 13 freeze–thaw cycles, GO-assisted MICP maintained the lowest void ratio and the most stable Pb immobilization performance among all treatments, demonstrating improved resistance against freeze–thaw-induced structural degradation. The results suggest that GO-assisted MICP can simultaneously improve Pb leaching control and soil-fabric stability, providing a promising low-carbon strategy for remediating heavy-metal-contaminated loess exposed to water-mediated freeze–thaw disturbance. Full article

Bedrock channel evolution is shaped by the combined effects of mechanical incision and weathering processes that operate under seasonal variability. This study employs numerical simulations to examine how bedload-impact abrasion and freeze–thaw weathering interact to drive bedrock channel cross-sectional adjustment under seasonal forcing of discharge and temperature. A set of numerical experiments systematically varies initial alluvial thickness, bedrock tensile strength, high-flow discharge, and freeze–thaw erosion depth. The results indicate sediment cover exerts strong control on abrasion efficiency. Thin alluvial cover enhances the tool effect and promotes center-focused incision, whereas thicker cover increasingly suppresses abrasion across the channel bed and stabilizes cross-sectional geometry. Higher bedrock tensile strength weakens only abrasion-driven incision, resulting in a reduced abrasion-to-weathering removal area ratio in more resistant substrates. Discharge shows a threshold-like influence on incision, with abrasion intensifying sharply once discharge exceeds the threshold and producing a deeper incision near the channel center. Freeze–thaw weathering removal is concentrated along channel banks and margins, promoting lateral modification at moderate prescribed erosion depths but becoming strongly suppressed at the largest depth due to enhanced debris production. Together, these responses define three characteristic regimes: abrasion-dominated, interaction-dominated, and freeze–thaw-dominated. These regimes offer a framework for interpreting coupled seasonal processes in bedrock channel evolution. Full article

Quantifying the soil moisture (SM) response to precipitation is pivotal for predicting hydrologic resilience and ecosystem stability in fragile cold regions. This is true in alpine permafrost environments characterized by variable precipitation phases and strong seasonal freeze–thaw dynamics. However, critical knowledge gaps persist due to the scarcity of high-resolution, multi-layer in situ observations in these remote areas. Using hourly data from three sites in the Tanggula Mountains (2020–2024), this study employs an event-based analytical framework combining logistic regression and linear regression to quantify multi-layer (10–100 cm) SM responses to rain, snow, and mixed-phase precipitation across seasons. Core findings indicate the following: (1) Precipitation thresholds with 80% probability of triggering SM responses rise sharply with depth during the cold period (10 cm: 1–11 mm; 50–100 cm: often >15 mm or unreachable) but increase gradually in the warm period (10 cm: 0.4–5 mm; 50 cm: <15 mm). Mixed-phase precipitation refers to the lowest amount of precipitation (0.4–2.5 mm at 10 cm), followed by rain (1–11 mm) and snow (2–5 mm). (2) Warm-period regression slopes are consistently steeper than cold-period slopes (at 10 cm, 0.0024 vs. 0.0010 for rainfall). Mixed-phase precipitation yields the steepest slopes, approximately 50% higher than rainfall at 10 cm in the warm period (0.0037 vs. 0.0024), due to its longer duration and dual-supply mode. For lag time, cold-period values are more widely dispersed due to multiple interacting factors, while warm-period values are concentrated; only warm-period rainfall exhibits a clear monotonic increase in lag time with depth, consistent with unsaturated flow theory. (3) The quantified regression slopes, threshold values, and phase-specific efficiencies provide transferable metrics for calibrating infiltration models and evaluating frozen-ground hydrology schemes. The finding that mixed-phase events are the primary driver of deep-layer recharge, despite accounting for a smaller fraction of the total event count, has direct implications for water resource assessment in high-altitude catchments where precipitation phase composition is often oversimplified. Overall, this study moves beyond qualitative descriptions by providing quantifiable, transferable metrics that advance the mechanistic understanding of precipitation–SM coupling in alpine permafrost regions. Full article

Quarry waste piles are heterogeneous engineered embankments that are susceptible to slope instability, yet early detection of pre-failure surface changes remains challenging due to complex surface conditions and measurement uncertainty. This study presents an integrated remote sensing-based framework for monitoring quarry waste pile instability by combining multi-temporal change detection with scale-dependent surface roughness analysis. The original contribution of the proposed framework lies in linking displacement-based change detection with multi-scale characterization of surface roughness, enabling both observed surface movement and topographical conditions associated with developing instability to be evaluated within a unified monitoring approach. Multi-epoch Unmanned Aerial Vehicle (UAV)-mounted Light Detection and Ranging (LiDAR) and photogrammetric point clouds were acquired before and after documented failure events at an active quarry site at active quarry sites located northeast of Montreal, Quebec, Canada. The regional climatic conditions, characterized by seasonal freeze–thaw cycles, rapid snowmelt, and periods of heavy rainfall, can promote water infiltration and elevated pore-water pressures, thereby increasing the susceptibility of these heterogeneous waste piles to slope instability. A standardized workflow was implemented, including precision alignment using a Recursive Iterative Closest Point (R-ICP) registration strategy, vegetation filtering with a multiscale CANUPO classifier, and uncertainty quantification through a Level of Detection (LoD) analysis. The resulting LoD thresholds were 10–15 cm for LiDAR-to-LiDAR comparisons and 34–36 cm for mixed-sensor datasets. Multi-scale roughness analysis revealed that zones which later experienced instability exhibited consistently higher and more heterogeneous roughness than adjacent stable areas within a well-defined linear scale range. A roughness-based A/D indicator enabled objective delineation of hazardous zones prior to failure. Post-failure monitoring showed surface smoothing following major displacement, followed by renewed roughness increases associated with secondary movements. These results demonstrate that scale-dependent roughness provides complementary information to displacement-based change detection, enabling potentially unstable areas to be identified and prioritized before substantial displacement becomes evident. The integrated framework can assist quarry managers in targeting field inspections and monitoring efforts toward higher-risk areas and support earlier preventive actions to reduce slope-failure risk. Full article

The prediction of shear strength in seasonally frozen silty clay is restricted by complex physical mechanisms and sparse experimental data. A self-supervised contrastive physics-informed neural network is proposed to overcome these limitations. Robust latent features are extracted from limited datasets via contrastive pretraining. Time-dependent constitutive equations and physical boundary conditions are simultaneously embedded into the loss function. This mathematical constraint ensures strict physical consistency during the modeling process. The proposed framework was validated using 100 independent laboratory samples prepared under controlled moisture content, freezing temperature, and thawing duration. The experimental results demonstrate the superior predictive accuracy of the proposed model. A coefficient of determination ($R^2$) of 0.988 was achieved on the test set, accompanied by minimized error metrics compared to conventional data-driven approaches. Consequently, a highly accurate and reliable methodology is established by this architecture for evaluating soil stability and supporting infrastructure design in cold regions. Full article

Seasonal freeze–thaw processes are important disturbances regulating soil carbon cycling in mid- to high-latitude mountain ecosystems, yet the mechanisms underlying carbon-fraction transformation and greenhouse gas emissions across vegetation types remain unclear. Here, we investigated five typical vegetation types along a 400–1500 m elevational gradient on the southern slope of the Altai Mountains. We measured topsoil organic carbon fractions, including particulate organic carbon (POC), mineral-associated organic carbon (MAOC), and dissolved organic carbon (DOC), extracellular enzyme activities, and CO₂ and CH₄ fluxes during the defrosting and melting periods to characterize vegetation-specific patterns of freeze–thaw-driven carbon stability. The results showed the following: (1) During the melting period, POC loss was significant in the low-elevation desert zone, riparian arbor forest, and floodplain meadow, with losses exceeding 90% in the latter two vegetation types. MAOC in the high-elevation mixed coniferous–broadleaf forest increased during the melting period. (2) The activities of carbon-acquiring enzymes, including CBH and AG, and the nitrogen-acquiring enzyme LAP generally decreased during the melting period, whereas the activity of the phosphorus-acquiring enzyme ALP increased in some vegetation types. This enzymatic shift may have partly constrained CO₂ release per unit of mineralized organic carbon, but it did not reverse the overall increase in carbon emissions during the melting period. (3) Carbon dynamics during the defrosting period were mainly characterized by the temporary retention of mineralization-derived carbon in dissolved forms within the DOC pool under low-temperature conditions, followed by a shift during the melting period toward carbon emissions jointly regulated by hydrothermal conditions and extracellular enzyme activities. This study showed pronounced differences in carbon responses among typical vegetation habitats during freeze–thaw processes. These differences may be jointly influenced by vegetation composition, elevation, hydrothermal conditions, and soil properties, revealing an elevational pattern of carbon loss at low elevations and carbon-fraction reorganization at high elevations. These findings suggest that carbon-balance assessments in arid mountain regions should incorporate stratified identification and classified evaluation based on the distribution of dominant vegetation types. Full article

Freeze–thaw (F/T) processes play a critical role in the regulation of soil hydrothermal dynamics, land–atmosphere energy exchange, and ecosystem functioning. The spaceborne global navigation satellite system reflectometry (GNSS-R) has shown great potential for land surface F/T state detection; however, its monitoring capability remains limited by spatial resolution, revisit interval, observation coverage, and complex land surface conditions. In this study, Tianmu-1 (TM-1) multi-GNSS-R observations were used to detect daily land surface F/T states over the mid-to-high latitudes of the Northern Hemisphere. First, surface reflectivity observations from multi-GNSS, including the Global Positioning System (GPS), BeiDou Navigation Satellite System (BDS), Galileo, and GLONASS, were fused using a weighted averaging method based on the number of specular reflection points. Then, TM-1 multi-GNSS-R reflectivity was used as the primary remote-sensing input, while vegetation water content (VWC), surface roughness, and snow cover information were introduced as auxiliary environmental variables. The Soil Moisture Active Passive (SMAP) F/T product was used to provide supervised reference labels for developing Bayesian-optimized extreme gradient boosting (XGBoost) models for F/T state classification. Evaluation against SMAP F/T reference labels showed that the multi-GNSS fusion model achieved an area under the curve (AUC) of 0.853 and an overall accuracy of 77.3% without incorporating snow cover information, outperforming the single-GNSS models. After incorporating snow cover information, the AUC increased to 0.959, and the overall accuracy reached 89.3%. Shapley additive explanations (SHAP) analysis further showed that snow cover made the largest contribution to the final model output, suggesting that its improvement effect may reflect both physical snow-related surface information and seasonal contextual information. An independent point-based comparison with in situ observations from the international soil moisture network (ISMN) showed that the TM-1 F/T classification accuracy reached 85.2% after incorporating snow cover information, which was comparable to that of the SMAP product. These results demonstrate that TM-1 multi-GNSS-R observations have promising potential for detecting land surface F/T states during the autumn–winter freezing development period, and that integrating multi-GNSS-R reflectivity with snow cover information can substantially improve classification performance and spatial consistency within the available observation period. Full article

Nowadays, alternative cost-effective and environmentally friendly waste materials have gained popularity over conventional chemical additives for the stabilization of weak soil in seasonal freeze–thaw (FT) areas. Molasses, a byproduct of sugar production, is utilized in various sectors; however, there are no studies in the literature concerning the use of molasses in the stabilization of clayey soil under FT cycles. To address this aim, in this study, a series of unconfined compressive strength (UCS) tests were conducted on both unstabilized and stabilized samples with molasses ratios ranging from 4% to 14%, subjected to 0, 5, 10, and 15 FT cycles following 7 and 28 days of curing. The assessment focused on the stress–strain (σ-ε) responses, unconfined compressive strength (q_u), failure strain (ε_f), secant modulus (E₅₀), and failure mode. The results demonstrated that maximum performances appeared with 10% molasses ratios, showing a 1.39–2.62-fold increase in the q_u values. As the curing period increased, the q_u and E₅₀ values increased significantly, while the ε_f values exhibited a diminishing trend. It was also observed that the FT cycles caused a dramatic reduction in the shear strength of unstabilized samples, ranging from approximately 42% to 69%; however, molasses-stabilized samples demonstrated higher resistance. Furthermore, XRD, SEM, and EDX analyses were carried out to investigate the mineralogical, microstructural, and chemical behaviors. Finally, an empirical equation was proposed to predict the q_u of molasses-stabilized soil subjected to FT cycles. Full article