Cold Regions Science and Technology最新文献_第8页

Coupling effects of temperature and water content on the dynamic properties of frozen red sandstone 温度和含水量对冻结红砂岩动力特性的耦合影响

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-11-06 DOI: 10.1016/j.coldregions.2025.104745

Jianhua Yang , Xianming Chen , Zhiwei Ye , Chi Yao , Xiaobo Zhang , Yongli Ma , Da Liu

In cold regions, the dynamic properties of frozen rock are a key consideration for blasting engineering in rock masses. However, the coupling effects of temperature and water content on them remain poorly understood in current research. In this study, dynamic impact tests were performed on red sandstone specimens with saturated water coefficients ranging from 0.2 to 1.0 under ambient and negative temperatures, based on the improved split Hopkinson pressure bar system, by integrating a real-time sub-zero temperature control module. The temperature influence factor (TIF) has been creatively defined, establishing the relationship between the dynamic parameters of ambient-temperature rocks and cryogenic rocks, thus filling the gap where no connection existed between them. The results demonstrate that, under a fixed moisture content, both the dynamic uniaxial compressive strength (σ_cd) and the dynamic elastic modulus (E_d) increase with decreasing temperature. Due to the influence of the saturation coefficient on the content of ice formed by phase change of water in rock pore (weakening effect of unfrozen water at low saturation coefficients→strengthening effect of ice at moderate saturation coefficients→deterioration effect of excessive ice at high saturation coefficients), both σ_cd and E_d of frozen red sandstone follow a three-stage evolution pattern of first decreasing, then increasing, and finally decreasing with increasing saturation coefficients. The TIF of σ_cd and E_d has a positive correlation trend with the saturation coefficient. Under the tested sub-zero conditions, TIF increases approximately linearly with decreasing temperature. Additionally, the specimen's aspect ratio, strain rate, and static compressive strength all significantly affect the rate of change in TIF with temperature.

在寒冷地区，冻结岩体的动力特性是岩体爆破工程的关键考虑因素。然而，目前的研究对温度和含水量对它们的耦合效应知之甚少。本研究基于改进的分离式霍普金森压杆系统，通过集成实时零度以下温度控制模块，对饱和水系数为0.2 ~ 1.0的红砂岩试件在环境温度和负温度下进行了动态冲击试验。创造性地定义了温度影响因子（TIF），建立了常温岩石与低温岩石动态参数之间的关系，填补了两者之间没有联系的空白。结果表明：在一定含水率下，随着温度的降低，动态单轴抗压强度（σcd）和动态弹性模量（Ed）均增大；由于饱和系数对岩石孔隙中水相变冰含量的影响（低饱和系数下未冻水的弱化作用→中等饱和系数下冰的强化作用→高饱和系数下过量冰的劣化作用），冻结红砂岩的σcd和Ed均呈现先减小后增大的三阶段演化规律；最后随着饱和系数的增大而减小。σcd和Ed的TIF与饱和系数呈正相关趋势。在测试的零下条件下，TIF随温度的降低近似线性增加。此外，试样的长径比、应变率和静态抗压强度都显著影响TIF随温度的变化率。

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引用次数: 0

Ice loads in ship-ice glancing impacts: Experimental investigation and validation of energy-based predictions 船冰掠射撞击中的冰载荷：基于能量预测的实验研究和验证

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-11-06 DOI: 10.1016/j.coldregions.2025.104744

Zongyu Jiang , Pentti Kujala , Spyros Hirdaris , Pauli Lehto , Henrik Toikka , Mikko Suominen

Arctic shipping has grown significantly in recent years, driven by diminishing sea ice and the pursuit of shorter shipping routes. However, the harsh Arctic environment poses risks to ships, particularly from ship-ice collisions, which can damage hulls and threaten safety. Accurate prediction of ice loads during such interactions is crucial for designing ice-going vessels. This study investigates ice loads induced by glancing impacts between a ship and a free-floating ice floe through a series of model-scale experiments conducted in calm water. A novel model ice material with stable compressive strength at room temperature was developed to ensure consistent test conditions. The experiments measured ice loads, ice indentation, and the motions of both the ship and ice models during impact. The results were compared with predictions from the energy-based Popov method, which evaluates ice loads using momentum and energy conservation principles. The study found that the Popov method provides reasonable predictions of ice loads, particularly in capturing the influence of ship speed, but tends to underestimate the measured loads. The contact location between the ship and ice floe has a significant influence on the magnitude of ice loads, with impacts near the bow shoulder generating higher forces compared to those closer to the stem. While the Popov method can qualitatively reflect the influence of contact location on ice loads, it significantly underestimates the strength of this effect. Visual observations suggest that the variation could be attributed to the ship-ice hydrodynamic interaction, which may not be captured by the Popov method. The findings highlight the importance of considering contact location and hydrodynamic effects in ice load predictions. In contrast, the Popov method overestimates ice indentation by assuming that all kinetic energy loss is absorbed by the ice failure, disregarding other energy dissipation mechanisms. This research contributes to the validation and refinement of theoretical models for ship-ice interactions, offering insights into the design of ice-going vessels operating in Arctic conditions.

近年来，在海冰减少和人们追求更短航线的推动下，北极航运显著增长。然而，恶劣的北极环境给船舶带来了风险，特别是船冰碰撞，这可能会损坏船体并威胁安全。在这种相互作用中准确预测冰荷载对于设计冰船至关重要。本研究通过在静水中进行的一系列模型比例尺实验，研究了船舶与自由浮冰之间的掠射碰撞所引起的冰荷载。为了保证试验条件的一致性，研制了一种室温下抗压强度稳定的新型冰材料模型。实验测量了冰的载荷、冰的压痕以及船和冰模型在撞击过程中的运动。结果与基于能量的波波夫方法的预测结果进行了比较，波波夫方法利用动量和能量守恒原理评估冰载荷。研究发现，波波夫方法提供了合理的冰负荷预测，特别是在捕捉船舶速度的影响时，但往往低估了测量的负荷。船舶与浮冰之间的接触位置对冰荷载的大小有显著影响，靠近船首肩的撞击产生的力比靠近船首杆的撞击产生的力大。虽然波波夫方法可以定性地反映接触位置对冰荷载的影响，但它明显低估了这种影响的强度。目视观察表明，这种变化可能归因于船-冰流体动力相互作用，这可能无法被波波夫方法捕获。研究结果强调了在冰荷载预测中考虑接触位置和水动力效应的重要性。相比之下，波波夫方法高估了冰压痕，因为它假设所有动能损失都被冰破坏吸收了，而忽略了其他能量耗散机制。这项研究有助于验证和完善船冰相互作用的理论模型，为在北极条件下运行的冰船的设计提供见解。

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引用次数: 0

Seasonal evolution of brackish ice microstructure during growth and decay processes 微咸冰生长和衰减过程中微观结构的季节性演变

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-11-03 DOI: 10.1016/j.coldregions.2025.104740

Miao Yu , Peng Lu , Hang Zhang , Guiyong Zhang , Lei Wang , Qingkai Wang , Zhijun Li

The physical properties of ice are primarily determined by its microstructure, such as gas bubbles and brine pockets within ice. However, the distributions and evolution patterns of these inclusions during ice freezing and melting remain poorly understood. Most studies therefore treat the ice microstructure as constant and ignore its seasonal variations. To investigate this issue, in situ experiments were conducted on a brackish lake to collect detailed information on the variations in the microstructure of ice using continuous sampling and a high-resolution imaging system. During the freezing phase, the volume fractions of gas bubbles and brine pockets remained relatively stable and decreased, respectively. Furthermore, the size of gas bubbles and brine pockets in the ice surface, middle, and bottom layers of ice increased clearly during the melting phase of ice due to different reasons. The nearly 30 % increase in gas bubbles observed in the middle layer was driven by ice temperature, while the increase in the surface layer was influenced by the net shortwave radiation. Additionally, the variation in the size distribution of inclusions was attributed to the merging process, which primarily occurred among smaller inclusions rather than among larger inclusions. The number of both gas and brine inclusions in the middle layer was found to decrease by 10 to 20 % for an increase in ice temperature by 1 °C, while this phenomenon was not observed in the surface or bottom layers. This study could improve our understanding of how ice microstructure changes.

冰的物理性质主要取决于其微观结构，如冰内的气泡和盐水袋。然而，这些包裹体在冰冻结和融化过程中的分布和演化模式仍然知之甚少。因此，大多数研究将冰的微观结构视为常数，而忽略了它的季节变化。为了研究这一问题，我们在一个微咸湖泊上进行了原位实验，利用连续采样和高分辨率成像系统收集了冰微观结构变化的详细信息。在冻结阶段，气泡和盐水袋的体积分数分别保持相对稳定和减小。在冰融化阶段，由于不同的原因，冰表面、中间和底部的气泡和盐水袋的大小明显增加。中层气泡增加近30%主要受冰温驱动，而表层气泡增加主要受净短波辐射影响。此外，包裹体尺寸分布的变化主要归因于合并过程，合并过程主要发生在较小的包裹体中，而不是在较大的包裹体中。研究发现，冰温每升高1°C，中间层中气体和盐水包裹体的数量减少10% ~ 20%，而在表层和底层均未观察到这种现象。这项研究可以提高我们对冰微观结构变化的理解。

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引用次数: 0

Closed-form solution method for mechanical response of isolated-span transmission line after ice shedding based on state discretization 基于状态离散化的隔跨输电线路脱冰后力学响应的闭式求解方法

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-11-03 DOI: 10.1016/j.coldregions.2025.104738

Zhao Yan , Si-yuan Wu , Xing Fu , Hong-nan Li , Hao Li , Zeng-hao Huang

Vibrations induced by ice-shedding in transmission lines can trigger flashover and conductor breakage, driving an urgent requirement for efficient response prediction methods. Existing theoretical approaches predominantly calculate maximum jump heights for conductors supported by tangent towers. However, the behavior of ground wires and conductors supported by angle and strain towers is similar to isolated spans, so their different response characteristics render traditional assumptions inapplicable, which leads to great computational deviations. To address this gap, the concept of effective weight is introduced, and two potential characteristics of dynamic tension variation are investigated in this study. A closed-form theoretical solution for the critical responses of transmission lines is developed based on state discretization. To validate its accuracy, comparative analyses are conducted using experimental data and finite element simulation results. Furthermore, the influence of various parameters on the ice-shedding response was systematically discussed. The results demonstrate that, compared to existing methods, the proposed method can provide more accurate predictions of maximum jump height and enables effective estimation of displacement and stress for isolated-span conductors and ground wires. Therefore, this method can significantly reduce analysis time and provide valuable evaluations for the structural design and deicing operations in practical engineering.

输电线路中冰脱落引起的振动会引发闪络和导线断裂，因此迫切需要有效的响应预测方法。现有的理论方法主要是计算由切塔支撑的导体的最大跳高。然而，由于角塔和应变塔支撑的接地线和导线的行为与孤立跨相似，因此它们的不同响应特性使得传统的假设不适用，从而导致了很大的计算偏差。为了解决这一问题，本文引入了有效重量的概念，并对动态张力变化的两个潜在特征进行了研究。在状态离散化的基础上，提出了输电线路临界响应的封闭理论解。为了验证其准确性，将实验数据与有限元模拟结果进行了对比分析。在此基础上，系统地讨论了各参数对消冰响应的影响。结果表明，与现有方法相比，该方法能更准确地预测最大跳高，并能有效地估计隔跨导线和接地线的位移和应力。因此，该方法可以大大缩短分析时间，为实际工程中的结构设计和除冰作业提供有价值的评估。

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引用次数: 0

Experimental and hypoplastic model investigation of frozen soil mechanics: Integrating confining pressure, temperature, and ice content effects 冻土力学的实验和发育不良模型研究：围压、温度和含冰量的综合影响

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-11-03 DOI: 10.1016/j.coldregions.2025.104742

Jiawei Zhang , Yongchao Zhang , Ke Ke , Lilin Li , Yanlong Li , Lele Liu , Changling Liu , Nengyou Wu

Frozen soils, widely distributed in polar, plateau, and high-latitude regions, have been experiencing accelerated degradation in recent decades due to climate change. This degradation alters the mechanical properties of frozen soils, posing threats to critical infrastructure construction and resource development, and potentially inducing geohazards. In this study, the mechanical behavior of frozen soils under different conditions was investigated through triaxial shear experiments. Subsequently, an eight-parameter hypoplastic model was established to predict the strength and deformation properties of frozen soil as influenced by temperature, confining pressure, and ice content. The experimental results indicate that lower temperatures and higher confining pressures enhance the mechanical properties of frozen soil. Conversely, ice content exhibits a threshold effect, whereby moderate ice cementation improves strength and stiffness whereas excessive ice leads to strength degradation. The proposed hypoplastic model shows good agreement with the experimental results, providing a reliable theoretical tool for analyzing the evolution of mechanical properties of frozen soil under varying environmental conditions.

近几十年来，由于气候变化，广泛分布于极地、高原和高纬度地区的冻土正在加速退化。这种退化改变了冻土的力学特性，对关键基础设施建设和资源开发构成威胁，并可能诱发地质灾害。通过三轴剪切试验，研究了不同条件下冻土的力学特性。随后，建立了8参数欠塑性模型，预测了温度、围压和含冰量对冻土强度和变形特性的影响。试验结果表明，较低的温度和较高的围压可以提高冻土的力学性能。相反，冰含量表现出阈值效应，即适度的冰胶结可以提高强度和刚度，而过量的冰则会导致强度下降。该模型与试验结果吻合较好，为分析不同环境条件下冻土力学特性的演变提供了可靠的理论工具。

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引用次数: 0

Numerical investigation of freeze-thaw induced water migration and instability of soil slope 冻土融水对土坡失稳影响的数值研究

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-11-01 DOI: 10.1016/j.coldregions.2025.104739

Yikai Wang, Shuai Zhang, Qi Zhang, Jinzhang Zhang

Freeze-thaw triggered slope failure has been widely reported through site investigations. As far as the authors are aware, the influence of water migration during freeze-thaw cycle on slope stability has not been fully investigated. Through a quantitative characterization of different phases in unsaturated soil, a thermo-hydraulic model was developed in this study to analyse heat and water migration in soil during freeze-thaw process. This model was validated against existing laboratory data. The computed pore water pressure (PWP) by the thermohydraulic model was then used to determine the factor of safety (FOS) of an unsaturated soil slope using the limit equilibrium method. Parametric study was conducted to investigate the effects of ground temperature and the location of water table on the FOSs of slopes during thawing. The computed results reveal a significant trend of water migration from the lower unfrozen zone towards the upper freezing front during the freezing process due to cryogenic suction. Subsequently, the release of the upward-migrated water contributes to an increase in the near-surface PWP during thawing. For a typical soil slope with a 45° slope angle, the surface PWP rises by 57 kPa after thawing compared to its initial hydrostatic condition. Consequently, the FOSs for shallow slopes can be reduced to less than 1.0. The parametric study shows that a slope is more prone to failure during thawing following a preceding winter with a lower ground temperature in previous winter and a higher water table.

冻融引发的边坡破坏已在现场调查中得到广泛报道。据作者所知，冻融循环过程中水迁移对边坡稳定性的影响尚未得到充分的研究。通过对非饱和土壤中不同阶段的定量表征，建立了冻融过程中土壤中热量和水分迁移的热水力模型。根据现有的实验室数据验证了该模型。利用热水力模型计算的孔隙水压力，采用极限平衡法确定非饱和土边坡的安全系数。通过参数化研究，探讨了地表温度和地下水位位置对边坡融化过程中FOSs的影响。计算结果表明，在冻结过程中，由于低温吸力的作用，水有明显的由下不冻结区向上冻结锋迁移的趋势。随后，向上迁移的水的释放有助于解冻期间近地表PWP的增加。对于坡角为45°的典型土质边坡，解冻后的地表PWP较初始水静力条件上升了57 kPa。因此，对于浅斜坡，FOSs可以降低到小于1.0。参数化研究表明，前一个冬季地温较低、地下水位较高的边坡在解冻过程中更容易发生破坏。

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引用次数: 0

Thermo-Hydro-Gaseous-Chemical-Mechanical (T-H-G-C-M) coupled modeling on seasonally unsaturated frozen saline soil (SUFSS) as railway subgrade 铁路路基季节性非饱和冻土（SUFSS）热-水-气-化学-力学耦合模型

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-10-30 DOI: 10.1016/j.coldregions.2025.104737

Wei GUO , Yuanlong DONG , Guoyao GAO

The condensation and sublimation of vapor in seasonally unsaturated frozen saline soil (SUFSS) influence the water and salt distributions, thereby influencing the ice crystal growth, salt crystallization, and soil deformation. A Thermo-Hydro-Gaseous-Chemical-Mechanical (T-H-G-C-M) coupled model was derived in this paper to investigate the effect of condensation and sublimation of vapor in the freezing process of SUFSS. The discretization method was used to solve unknowns. The governing equations are discretized using COMSOL Multiphysics software. The presented model was applied to predict three laboratory model tests and a field monitoring data in literature. The well agreements between these results approved the accuracy of the proposed coupled model. The proposed coupled model could effectively consider the effects of condensation and sublimation of vapor in the pores, as well as the dissolution of dry air and salts in the liquid phase, on frost heave and salt expansion generated deformation of SUFSS.

季节性非饱和冻土（SUFSS）水汽的凝结和升华影响水盐分布，从而影响冰晶生长、盐结晶和土壤变形。本文建立了一个热-氢-气-化学-机械（T-H-G-C-M）耦合模型，研究了水蒸气在SUFSS冻结过程中的凝结和升华作用。采用离散化方法求解未知量。利用COMSOL Multiphysics软件对控制方程进行离散化。该模型已应用于文献中三个实验室模型试验和一个现场监测数据的预测。这些结果吻合良好，证明了所提出的耦合模型的准确性。所建立的耦合模型可以有效地考虑孔隙中水蒸气的凝结和升华，以及干燥空气和盐在液相中的溶解对冻胀和盐膨胀引起的SUFSS变形的影响。

引用次数: 0

Influence of structural characteristics on the mechanical behavior and failure mechanisms of frozen clay 结构特性对冻结粘土力学行为及破坏机制的影响

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-10-28 DOI: 10.1016/j.coldregions.2025.104736

Sheng Shi , Guanfu Wang , Decheng Feng , Feng Zhang

The strength and deformation properties of frozen soil are significant indicators to evaluate the stability and safety of infrastructures during construction and operation in cold regions. The distinctive nature and complexity of frozen soil are mainly reflected in its sensitivity to temperature changes and its inherent structural deformation features. This research focuses on the influence of frozen clay structural characteristics on its mechanical and deformation characteristics, and the mechanical behaviors of frozen clay with different structures were studied using a GDS triaxial test system. The influences of structural features and stress levels on its mechanical properties were analyzed, and the effect of confining pressure on its mechanical parameters was investigated. The variations in cracking strength and dilatancy strength of frozen clay with different structures under various confining pressure were analyzed. Finally, the mechanical properties of frozen clay with different structures were investigated using COMSOL, and the failure mechanisms were revealed.

冻土的强度和变形特性是评价寒区基础设施建设和运行过程中稳定性和安全性的重要指标。冻土的独特性和复杂性主要体现在其对温度变化的敏感性和其固有的结构变形特征上。研究了冻结粘土结构特性对其力学和变形特性的影响，采用GDS三轴试验系统研究了不同结构冻结粘土的力学行为。分析了结构特征和应力水平对其力学性能的影响，研究了围压对其力学参数的影响。分析了不同结构冻结粘土在不同围压作用下的抗裂强度和抗剪强度变化规律。最后，利用COMSOL软件对不同结构冻结粘土的力学性能进行了研究，揭示了其破坏机理。

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引用次数: 0

Initialization of coupled thermo-hydro-mechanical models of permafrost terrain using the frozen-ground-fem package 冻土地形热-水-力耦合模型的冻土有限元程序初始化

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-10-25 DOI: 10.1016/j.coldregions.2025.104732

Anna Pekinasova , Jocelyn L. Hayley , Brandon Karchewski

Permafrost degradation under climate change poses growing risks to infrastructure and environmental stability in cold regions. Processes such as frost heave, thaw settlement, and thermokarst are intensifying due to rising temperatures, changing precipitation, and evolving snow and surface hydrology. While many thermal models capture heat transfer in permafrost, they often overlook the coupled thermal, hydraulic, and mechanical (THM) interactions that are crucial for predicting thaw-induced deformation and consolidation. A critical yet underreported aspect of permafrost modelling is the “spin-up” phase: an initialization procedure that applies cyclic boundary forcing to stabilize subsurface conditions before transient simulations. Prior studies, including Ross et al. (2022), demonstrated that thermal spin-up alone can require over 10,000 cycles for permafrost ground, but neglected hydromechanical effects such as void ratio evolution and stress redistribution. In this study, we extend Ross et al.'s approach by implementing a coupled THM spin-up strategy using the open-source Python 3 package frozen-ground-fem. This one-dimensional, large-strain finite element framework solves for both temperature and void ratio, incorporating phase change, cryosuction, nonlinear constitutive laws, and residual stress initialization. Examples using Ross et al.'s input data illustrate how coupled initialization improves stability and accuracy of permafrost predictions. Our results demonstrate that joint thermal and hydromechanical spin-up significantly alters equilibrium profiles and enhances simulation reliability. The frozen-ground-fem model is freely available on GitHub, supporting open and reproducible development of climate-resilient permafrost infrastructure models.

气候变化下的冻土退化对寒冷地区的基础设施和环境稳定构成越来越大的风险。由于气温上升、降水变化以及积雪和地表水文的演变，冻胀、融化沉降和热岩溶等过程正在加剧。虽然许多热模型捕捉了永久冻土中的热量传递，但它们往往忽略了热、水力和机械（THM）耦合相互作用，而这些相互作用对于预测融化引起的变形和固结至关重要。多年冻土模拟的一个关键但未被充分报道的方面是“自旋上升”阶段：在瞬态模拟之前，应用循环边界强迫来稳定地下条件的初始化过程。包括Ross等人（2022）在内的先前研究表明，仅热自旋就可能需要超过10,000个循环，但忽略了流体力学效应，如孔隙比演化和应力重新分布。在本研究中，我们扩展了Ross等人的方法，使用开源Python 3包frozen-ground-fem实现了一个耦合的THM自旋策略。这种一维、大应变的有限元框架同时解决了温度和空隙比的问题，结合了相变、低温吸力、非线性本构定律和残余应力初始化。使用Ross等人输入数据的例子说明了耦合初始化如何提高永久冻土预测的稳定性和准确性。研究结果表明，关节热和流体力学自旋显著改变了平衡剖面，提高了模拟的可靠性。冻土有限元模型可以在GitHub上免费获得，支持开放和可复制的气候适应性永久冻土基础设施模型的开发。

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引用次数: 0

Multifractal characteristics of slate pore structure based on nuclear magnetic resonance in cold region 寒区板岩孔隙结构核磁共振多重分形特征

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2025-10-25 DOI: 10.1016/j.coldregions.2025.104733

Li Yin , Daguo Wang , Jianguo Lu , Jiajian Jin , Jiajia Gao , Yun Liu

The physical and mechanical properties of rocks in high-altitude cold regions are prone to degradation, often leading to severe geological disasters. In this study, combining nuclear magnetic resonance (NMR), uniaxial compression strength (UCS) tests and fractal theory, freeze-thaw (FT) cycle experiments under multiple environmental conditions including freeze-thaw in air (FT-A), water (FT-W) and alternating dry-wet cycle (DW-FT) were conducted for 0, 5, 10, 15, 20, 25, 30, 35, and 40 cycles. The temperature ranged from −15 °C to 20 °C. DW cycles included drying for 12.0 h at 105 °C, and then immersing in water for 12.0 h. NMR was employed to quantify pore size distributions by transverse relaxation time (T₂) spectra, providing the probability density dataset essential for multifractal analysis. The findings indicated that the porosity of slate significantly raised with number of freeze-thaw (FT) cycles, with more pronounced increase observed under FT-W or DW-FT conditions. Although the DW cycles had a relatively limited influence on porosity, they resulted in a noteworthy reduction in the mechanical properties of the slate. Additionally, the mesopores and macropores of slate exhibited monofractal characteristics. The fractal dimension of mesopores (D_b) positively correlated as the FT cycles, whereas the opposite results occurred for fractal dimension of macropores (D_c). Furthermore, multifractal parameters (ΔD, Δα) were employed to provide quantitative characterization of the heterogeneity characteristics within micropores and macropores. Generally, the pore heterogeneity increased with FT cycles, with macropores contributing significantly to the heterogeneity of pore structure. Moreover, the mechanical strength of slate under FT cycles was negatively correlated with both the pore heterogeneity parameter and Hurst index (H). In contrast, the mechanical properties of slate under DW conditions showed no significant correlation with the pore heterogeneity parameter. The results demonstrated the applicability of multifractal theory in characterizing the pore structure of slate. Furthermore, it provided a novel perspective on the connection between the microstructure characteristics and macroscopic properties of rocks exposed to FT cycles.

高海拔寒区岩石的物理力学性质容易退化，往往导致严重的地质灾害。本研究结合核磁共振（NMR）、单轴抗压强度（UCS）试验和分形理论，在空气（FT- a）、水（FT- w）和干湿交替循环（DW-FT）等多种环境条件下进行了0、5、10、15、20、25、30、35和40个循环的冻融（FT）循环试验。温度范围：- 15℃~ 20℃。DW循环包括在105°C下干燥12.0 h，然后在水中浸泡12.0 h。利用核磁共振通过横向弛豫时间（T₂）谱来量化孔径分布，为多重分形分析提供必要的概率密度数据。结果表明：随着冻融循环次数的增加，板岩孔隙度显著升高，其中冻融-冻融和dw -冻融条件下孔隙度增加更为明显；虽然DW旋回对孔隙度的影响相对有限，但却显著降低了板岩的力学性能。板岩的中孔和大孔均表现出单分形特征。中孔（Db）的分形维数与FT旋回呈正相关，而大孔（Dc）的分形维数则相反。利用多重分形参数（ΔD， Δα）定量表征了微孔和大孔的非均质性特征。总体上，孔隙非均质性随FT旋回增大，其中大孔隙对孔隙结构的非均质性贡献显著。此外，板岩在FT旋回作用下的力学强度与孔隙非均质性参数和Hurst指数(H)均呈负相关。相比之下，DW条件下板岩的力学性质与孔隙非均质性参数无显著相关性。结果表明多重分形理论在板岩孔隙结构表征中的适用性。此外，它还为研究受FT旋回作用的岩石微观结构特征与宏观性质之间的联系提供了新的视角。

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引用次数: 0