Temperature and humidity variations in burial stone relics can easily cause water vapor condensation, which is an important factor leading to their deterioration. However, the water vapor condensation mechanism and the evaluation of risk ratings have always been difficult problems in the protection of cultural relics. In this study, the water vapor condensation mechanism in Yang Can's tomb was comprehensively investigated through on-site monitoring, indoor experiments and software simulations, on the basis of which a physical model of water vapor condensation in this tomb was established and a water vapor condensation risk rating assessment method was proposed. The proposed method considers the difference between the dew point and wall temperatures within the tomb (dew–wall temperature difference) and the duration of water vapor condensation, and corresponding preventive and control measures were formulated for different risk ratings. The study revealed that when the wall temperature of the chamber is lower than the dew point temperature, water vapor starts to condense. The larger the dew–wall temperature difference is, the greater the risk of condensation. In addition, specific water vapor condensation prevention and control measures were proposed for Yang Can's tomb, and the prevention and control effects were simulated. The simulation results showed that favorable prevention and control effects could be achieved, and the proposed measures could be applied in practice. This study holds notable significance for investigating the water vapor condensation mechanism and evaluating the risk ratings of burial stone relics and provides a theoretical basis and reference for water vapor condensation prevention and control in burial stone relics.

The nature of stone relic bodies is mainly determined by their stratigraphic properties; large open-air stone relics are affected by the stratigraphic span in space and have variations in weathering, and the systematic study of these variations is relevant to the prevention and treatment of weathering and restoration on the premise of the research and development of materials. Traditional research on the weathering of stone relics is usually focused on local or small-scale analysis, which uses qualitative evaluations by employing engineering geology techniques to determine weathering levels. However, quantitative research is relatively rare because large open-air stone relics lack systematic and comprehensive research. To systematically study the degree of weathering of large stone relics and quantify their variations, a method for determining the degree of weathering variation in large stone relics from macro- and micro perspectives was established by using a variety of experimental methods with combined testing to carry out a systematic study of the degree of weathering. The results show that there are obvious variations in the degree of weathering of large open-air stone relics and stratigraphic stratification of the rocks forming these relics have been carried out through field investigations and identifications using rock-thin sections. There are variations in mineral composition and elemental content between different layers, and SiO₂/(CaO+Al₂O₃ + Fe₂O₃) was chosen to characterize the loss of colloids from large open-air stone relics. Al₂O₃/(K₂O+CaO) was chosen to react with the degree of chemical weathering of large open-air stone relics, and a comprehensive comparative analysis of the variations between the layers of large open-air stone relics was carried out. The microscopic pore structures also differ between different layers, and the permeability of layers with dominant distributions of large pore-size pores is greater, which provides more convenient channels for water seepage, thus leading to more severe weathering. This study provides a new quantitative method for studying the weathering variations of large stone relics and provides a scientific basis for the prevention and control of weathering damage to large stone relics.

Rainfall is a major trigger for loess landslides, and understanding the associated deformation and failure mechanisms is essential for effective hazard mitigation. This study employed physical model experiments to investigate the hydrological response, deformation behavior, and failure evolution of homogeneous loess slopes subjected to intermittent rainfall. Key parameters, including volumetric water content, pore water pressure, wetting front migration, and displacement, were continuously monitored throughout the tests. The results revealed periodic fluctuations in hydrological parameters and spatially heterogeneous responses across the slope. Repeated transitions between saturated and unsaturated conditions, combined with surface runoff erosion and seepage-induced forces, contributed to a progressive reduction in soil shear strength and increased slope instability. The failure process evolved through three distinct stages: toe erosion, fissure expansion, and gully erosion. These findings improve the understanding of rainfall-induced loess slope failures and support the development of stage-specific hazard mitigation strategies.

Burial stone relics remain in a humid, semi-enclosed environment for long periods, and temperature and humidity variations can cause deterioration acceleration. Yang Can’s tomb was selected as the research object, and field monitoring and simulations were performed to investigate the characteristics of temperature and humidity variations, after which the simulation results were evaluated. The monitoring results showed that solar radiation, rainfall, wind speed, and depth of entry are important factors affecting the variation in the temperature and humidity of burial stone relics. The temperature outside the chamber is greatly affected by seasonal variations, while the humidity inside the chamber is influenced by seasonal variations, so appropriate measures should be implemented inside and outside the chamber during different seasons to alleviate deterioration. On the basis of the above analysis, a temperature and humidity model for the interior chamber of burial stone relics was established in COMSOL software 5.6, combined with a porous medium heat transfer model and computational fluid dynamics (CFD) model. The temperature and humidity inside the chamber can be calculated by the temperature and humidity outside the chamber. This study provides data support for hydrothermal, condensation and other related studies of burial stone relics.

Loess landslides are one of the most important natural hazards among various landslide types in China, and rainfall is the main factor triggering loess slope instability. To gain deeper insights into the processes behind slope failure triggered by precipitation, this study conducted an indoor slope rainfall modelling test based on the case of the Shixiakou landslide in Jinzhou, Lanzhou. The test employed a custom-built rainfall simulation device, precisely controlling rainfall intensity and duration to mimic natural rainfall conditions. Soil moisture sensors, pore-water pressure transducers, and strain gauges were strategically installed within the loess slope model to monitor soil moisture dynamics, pore-water pressure variations, and lateral stress distribution in real-time. This investigation examined the progressive failure mechanism of loess slopes under rainfall infiltration through integrated monitoring. The experimental results demonstrate that sustained precipitation triggers a sequential failure process characterized by four distinct phases: initial surface scouring, subsequent basal slope instability, progressive mid-slope shear failure, and ultimate crown section collapse, and finally traction failure mode. It is worth noting that cracks play a crucial role in slope failure by creating preferential channels for water infiltration and subsequent failure development.

The safe disposal of high-level radioactive waste (HLW) is a significant challenge in the nuclear industry. As the buffer backfill material for deep geological disposal engineering barriers, the shrinkage characteristics of bentonite–sand mixtures are critical to the long-term stability of repositories. This study systematically conducted drying shrinkage tests using an improved thin-film technique under varying sand contents R_s (0–50%), salt solution concentrations (0–1.5 mol/L), and ion types (Na⁺, Mg²⁺, Ca²⁺, Cl⁻, SO₄²⁻). The mechanisms of the effects of sand content and salt solutions on the shrinkage behavior of bentonite were revealed based on the results. In addition, the rationality of the MCG-B model in simulating the shrinkage characteristics of mixtures was also discussed. The results show that a sand content of 30% is the minimum sand content for inhibiting the shrinkage behavior of bentonite–sand mixtures observed in this work: below this ratio, bentonite dominates the shrinkage process, and samples are prone to cracking due to uneven matrix suction; above this ratio, quartz sand forms a rigid skeleton that significantly inhibits volume shrinkage and accelerates water evaporation. Salt solutions suppress shrinkage by compressing the thickness of the diffuse double layer and inducing ion crystallization. Higher cation concentrations and valences (Mg²⁺ > Na⁺ > Ca²⁺) enhance the inhibitory effect. Crystalline salts such as Na₂SO₄ cause measurement deviations in water content due to hydration and delay the shrinkage process. However, NaCl solutions effectively inhibit shrinkage with minimal impact on shrinkage time. Fitting results with the MCG-B model (Coefficient of determination > 0.97) demonstrate that the MCG-B model can empirically describe the results of thin-film technique experiment, though the model’s prediction accuracy decreases for the residual shrinkage stage at high sand contents (>40%). This study provides a theoretical basis for optimizing buffer material proportions and curing processes, with significant implications for the long-term safety of HLW repositories.