Freeze-thaw cycles in seasonally frozen soil affect the boundary conditions of aqueducts with pile foundations, consequently impacting their seismic performance. To explore the damage characteristics and seismic behaviour of aqueduct bent frames in such regions, a custom testing apparatus with an integrated cooling system was developed. Two 1/15 scale models of reinforced concrete aqueduct bent frames with pile foundations were constructed and subjected to pseudo-static testing under both unfrozen and frozen soil conditions. The findings revealed that ground soil freezing has minimal impact on the ultimate bearing capacity and energy dissipation of the bent frame-pile-soil system, but significantly enhances its initial stiffness. Additionally, the frozen soil layer exerts a stronger embedding effect on the pile cap, ensuring the stability of the pile foundation during earthquakes. However, under large seismic loads, aqueduct bent frames experience greater damage and residual deformation in frozen soil compared to unfrozen soil conditions. Therefore, the presence of a seasonally frozen soil layer somewhat compromises the seismic performance of aqueduct bent frames. Subsequently, a finite element model considering pile-soil interaction (PSI) and frozen soil hydro-thermal effects was developed for aqueduct bent frames and validated against experimental results. This provides an effective method for predicting their seismic behaviors in seasonally frozen soil regions. Furthermore, based on the seismic damage characteristics of aqueduct bent frame with pile foundations observed in pseudo-static tests, a novel selfadaptive aqueduct bent frame system was designed to mitigate the adverse effects of seasonally frozen soil layer on seismic performance. This system is rooted in the principle of balancing resistance with adaptability, rather than solely depending on resistance. The seismic performance of this innovative system was then discussed, providing valuable insights for future seismic design of reinforced concrete aqueduct bent frames with pile foundations in seasonally frozen soil regions.

In cold regions, and considering the increasing concerns regarding climate change, it is crucial to assess soil stabilisation techniques under adverse environmental conditions. The study addresses the challenge of forecasting geotechnical properties of lime-stabilised clayey soils subjected to freeze-thaw conditions. A model is proposed to accurately predict the unconfined compressive strength (UCS) of lime-stabilised clayey soils exposed to freeze-thaw cycles. As the prediction of UCS is essential in construction engineering, the use of the model is a viable early-phase alternative to time-consuming laboratory testing procedures. This research aims to propose a robust predictive model using readily accessible soil parameters. A comprehensive statistical model for predicting UCS was developed and validated using data sourced from the scientific literature. An extensive parametric analysis was conducted to assess the predictive performance of the developed model. The findings underscore the capability of statistical models to predict UCS of stabilised soils demonstrating their valuable contribution to this area of study.

A share-point is a cutting edge of the ploughshare, the crucial component of a horizontally reversible plough (HRP). Our previous trials in sandy loam soil indicated that severe abrasion/attrition wear with white materials appeared at the share-point in the high-speed shifting tillage operation of the HRP. This mechanical fatigue was demonstrated to be caused by the flowing soil-tool interaction. But whether the white materials are associated with the thermal effects due to the high-speed tillage is not known. This paper extended our previous work to evaluate the thermal effects by using a combined multi-body dynamics analysis (MDA) and fluid-solid-thermal simulation. The dynamic interaction between soil and share-point was studied with the MDA approach. Based on the generated tillage forces through the MDA, a fluid-solid-thermal model of the ploughshare was developed to investigate the specific quantitative results, maximum stresses and temperatures observed at the share-point, which were further compared with the published worn-lands at the same tillage conditions (such as tillage speed and depth). The comparisons showed that the maximum coupled stresses and tillage temperatures in this study both appeared at the share-point, particularly at the most severe abrasion/attrition with white materials, and that they were both varied with the different working conditions or the different tillage behaviours. Our findings demonstrate that the high-speed shifting operation of HRP has the thermal effects on the share-point wear due to the fact that the greatly varied tillage temperatures can accelerate to impact the surface integrity because of the thermal stresses detrimental to the micro-shape or size shape at the share-point section. This result may add to the knowledge base usefully applicable to the design of the high-speed mouldboard.

The stimulation of shale reservoirs frequently involves significant shear failure, which is crucial for creating fracture networks and enhancing permeability to boost production. As the depth of extraction increases, the impact of elevated temperatures on the anisotropic shear strength and failure mechanisms of shale becomes pronounced, yet there is a notable lack of relevant research. This study conducts, for the first time, direct shear experiment on shales at four different temperatures and seven bedding angles. By employing acoustic emission (AE) and digital image correlation (DIC) techniques, the evolution of damage and the mechanism of crack propagation under anisotropic direct shearing at varying temperatures is revealed. The results indicate that both shear displacement and strength of shale increase with temperature across different bedding angles. Additionally, shale demonstrates distinct brittle failure characteristics under various conditions during direct shearing tests. The types of anisotropic shear failure observed under the influence of temperature include central shearing fracture, central shearing with secondary fracture, and deflected slip along the bedding. Moreover, the temperature effect enhances shear-induced crack propagation along bedding planes. Shear failure in shale predominantly occurs during higher loading stages, which coincide with a substantial amount of AE signals. Finally, the introduction of the anisotropy index and temperature sensitivity coefficient further elucidates the interaction mechanism between thermal effects and anisotropy. This study offers a novel methodology to explore the anisotropic shear failure behavior of shale under elevated temperatures, and also provides crucial theoretical and experimental insights into shear failure behavior relevant to practical shale reservoir stimulation. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

The long-term safety and durability of anchor systems are the focus of slope maintenance management and sustainable operation. This study presents the observed temperature, humidity, and anchor bolt stress at varying depths from four-year remote real-time monitoring of the selected loess highway cut-slope. The potential correlation between slope hydrothermal environment and anchor stress is analyzed. The anchor serviceability and durability were evaluated by establishing a time-dependent mathematical model of axial forces. The results show that the slope shallow loess exhibited hydro-thermal fluctuations annually during operation, subjecting the loess to continuous dry-wet cycles. Soil elastic deformation induces anchor axial force fluctuations due to hydro-thermo effects, while damage creep leads to the annual increase in axial force peaks and valleys. The increase in axial force is more significant at the upper slope and lower slope, thereby increasing the risk of retrogressive landslides in loess slopes. The time-dependent model of anchor axial force composing negative exponential and sine functions was proposed. The cyclic amplitudes, lower limits, and periods of temperature and humidity in slope can determine the model coefficients. The development patterns of axial force are classified into stable type, slow growth type, and accelerated growth type according to the characteristics of the model coefficients. Predicted results indicate that the anchor axial forces are lower than the landslide threshold within 30 years of slope operation, ensuring long safety and serviceability. Results provide a reference for the long-term safety evaluation and formulation of maintenance plans for loess slopes reinforced by anchor systems.

Plastic-bonded granular materials (PBM) are widely used in industrial sectors, including building construction, abrasive applications, and defense applications such as plastic-bonded explosives. The mechanical behavior of PBM is highly nonlinear, irreversible, rate dependent, and temperature sensitive governed by various micromechanical attributions such as grain crushing and binder damage. This paper presents a thermodynamically consistent, microstructure-informed constitutive model to capture these characteristic behaviors of PBM. Key features of the model include a breakage internal variable to upscale the grain-scale information to the continuum level and to predict grain size evolution under mechanical loading. In addition, a damage internal state variable is introduced to account for the damage, deterioration, and debonding of the binder matrix upon loading. Temperature is taken as a fundamental external state variable to handle non-isothermal loading paths. The proposed model is able to capture with good accuracy several important aspects of the mechanical properties of PBM, such as pressure-dependent elasticity, pressure-dependent yield strength, brittle-to-ductile transition, temperature dependency, and rate dependency in the post-yielding regime. The model is validated against multiple published datasets obtained from confined and unconfined compression tests, covering various PBM compositions, confining pressures, temperatures, and strain rates.

This paper explores the influence of two thermal loading protocols on the evolutions of stress state and soil consolidation characteristics during subsequent mechanical loading. We employed a specially designed thermal consolidometer to conduct a series of drained heating tests with temperature gradient across a saturated kaolin specimen at different levels of vertical effective stress. The thermal consolidometer accommodated for (1) continuous measurements of excess pore water pressure and temperature at different locations within a specimen; and (2) establishment of a steady nonuniform soil temperature distribution, a condition that often exists in the field. Staged and cyclic thermal loading revealed the influences of vertical effective stress on total and nonrecoverable thermal strain. Continuous measurements of pore pressure and soil volume change traced the evolution of average vertical effective stress with void ratio. While the negative pore pressure measurements at the end of thermal consolidation of normally consolidated clay suggested a pseudo-overconsolidated behavior upon heating at low values of vertical effectives stress, such a tendency diminished with an increase in stress level. A gradual shift in normal consolidation line at ambient temperature suggested continuous hardening of a normally consolidated specimen when subjected to repeated thermal loading cycles in the past.

This paper presents a new and rigorous method for simulating thermo-elasto-plastic responses of soil during the cylindrical cavity expansion process under undrained conditions. The soil is modeled by a modified nonisothermal unified hardening model, which can properly consider thermal effects on mechanical responses, thermally induced excess pore water pressure as well as the overconsolidation characteristics. The temperaturedependent governing equations are derived by combining equilibrium equations and constitutive relations. New solution algorithms are developed to solve governing equations and update temperature -related parameters during the expansion process. Two typical scenarios, one is cavity expansion under different temperatures and another is temperature variation after expansion, are simulated. The proposed computational approach is validated through comparisons with results obtained from Abaqus numerical simulations, non -isothermal analyses, and experimental data. As demonstrated by extensive parametric studies, the proposed computational approach can reasonably capture the influence of temperature on cavity expansion, which can be further applied, modified, and developed for various industrial and geophysical problems involving thermoplastic soils.

Increment of wildfire causes numerous disturbances and irregularities that jeopardize a sustainable society and reliable infrastructure. Due to the rigorous burns, the soil particles may breakdown due to thermal effects leading to a significant loss of the physical and mechanical properties of the soil mass, including reduced modules and strength and subsequent major problems such as soil erosion and near-surface slope slides. Many ambiguities are tied up with the multi-physics process of wildfire-burnt soil, the vegetation anchoring effect on soil strength, and the alteration of micro-scale soil properties. This study presents an innovative thermal-mechanical coupled model to simulate rock damage and breakage during heating-cooling processes. A series of simulations are carried out to capture the behaviors of rock samples under heating-cooling and subsequent compressive loadings using a two-dimensional discrete element method (DEM) model. The results suggest that the effect of mild wildfire on the strength and modulus reduction of rock is negligible. But the reduction of strength and modulus could be as high as 53% and 12%, respectively, under severe wildfire conditions.

In cold regions, the thermal effect of accumulated water on underlying permafrost and permafrost subgrade remains a significant hazard causing engineering risks. Water depth of accumulated water may be an important influence factor of permafrost thermal stability, but there is lack of qualitative and quantitative research about that. In this study, equivalent thermal conductivity theory and solid heat transfer theory have been used to establish the calculation model for simulating heat transfer in water and soil. Thereafter, the accuracy and reliability of the calculation model are checked by monitored data and subsequently used to analyze the thermal erosion of water on underlying permafrost and permafrost under the embankment. These simulation results show that shallow water can protect permafrost and deeper water disrupts the thermal stability of underlying permafrost. The thermal effect extent of water is primarily determined by its depth, and the concept of critical depth and stable depth of accumulated water has been proposed. Moreover, the temperature field of permafrost under embankment can be changed by the slope toe water. In addition, the thermal effect range of the slope toe water is limited by the thermal influence radius, which increases with the depth of standing water. These findings provide support as well as a fundamental base for environmental issues arising from the accumulated water. These observations will, thus, also be valuable to further engineering environment studies in cold regions.