Current snow erosion models predominantly depend on threshold friction velocity. However, considering the wind speed fluctuation and the randomness of the particle position on the snow bed, the force on the snow bed particles is highly randomized. To address this, a probability-based snow particle erosion model is proposed in this study, which accounts for the influence of wind speed fluctuations on snow particle entrainment. By integrating the Eulerian-Lagrangian method, the model predicts the erosion, rebound, and redeposition processes of snow particles without relying on a threshold friction velocity. To validate the model, we employ field measurements and wind tunnel data from established studies, demonstrating excellent agreement between numerical predictions and measured results. At the same time, through the comparison of the predicted results of the cloud map, we found that the snow depth minima are generally located in the local high friction velocity region, while the snow depth maxima are generally located in the region where the friction velocity changes sharply along the space and is close to the low friction velocity. The Discrete Phase Model (DPM) simulations used in this paper elucidate the underlying mechanics, demonstrating how particle-laden flow interactions drive these spatial correlations, which helps to preliminarily estimate the location of extreme snow depths based on friction velocity cloud images. Furthermore, this paper proposes a mesh refinement method based on the simulation approach, enabling its application to full-scale drifting snow dynamics simulations on large-span building roofs.

As a typical structure sensitive to wind and snow loads, the stability of single-layer reticulated shells is significantly affected by wind and snow loads. This paper applied CFD simulation and elastic-plastic time history analysis of structures to study the influence of wind and snow load coupling effects on the stability of single-layer cylindrical reticulated shells. Firstly, the typical distribution characteristics of the snowdrift under various inflow velocities on the cylindrical roof were identified through CFD simulation. Afterwards, the influence of the shape and height of the snowdrift on wind and snow fields around the cylindrical roof was discussed. Finally, the critical wind velocity of single-layer cylindrical reticulated shells with different stable snowdrifts was calculated, and the influence of the coupling effect of wind and snow loads on their stability was analyzed. The results indicate that under different inflow wind velocities, the cylindrical roof has four typical snow distribution patterns. The shape and height of the snowdrift seriously affect the distribution of wind and snow fields around the cylindrical roof. Considering the coupling effects of wind and snow loads, which significantly reduce the critical wind pressure of structures, the safety factor in traditional design methods should be increased by 1.7–2.0 times to ensure structural integrity. © 2025 Elsevier Ltd

Climate changes have led to an increase in the frequency and severity of rain-on-snow (ROS) events, risking structural safety with increasing roof snow loads. These events involve melting, freezing, and compaction induced by water infiltration in roof snowpacks. Existing models assume snow as a homogeneous medium with uniform ROS load distribution while ignoring critical phenomena like phase changes, heterogeneity, and evolution of snowpack's properties that alter water retention in snow. Although snow load is adjusted based on slope and roof geometry, these adjustments are not considered for ROS surcharge load. A two-dimensional coupled energy-mass (EM) transfer model using the Multi-point Flux Approximation method (MPFA) is employed to simulate ROS load on sloped roofs along with heat exchange, melting, refreezing, and compaction effects. Compared to simplified mass transfer models, the EM transfer model exhibits superior predictive capabilities when evaluated against experimental results. Although melting and compaction significantly increased the density, reducing porosity and permeability, the melted water accelerated saturation at the bottom boundary, enabling quicker outflow conditions. A non-uniform triangular water retention pattern at the lower roof edge was observed in both models, suggesting that heterogeneity has minimal impact on the water retention profile. Under the studied ROS load conditions, the ROS load at the roof edge is 1.6 times the overall ROS load due to non-uniform water retention. The study highlights the inadequacy of existing design code as the design ROS load is inapplicable to the studied ROS condition, despite localized loads being close to design ROS load (0.38 kN/m2). © 2025

A blizzard can last for a long time. Investigating the distribution of snow on roofs helps to reduce the occurrence of snow-induced engineering disasters. Previous studies have paid little attention to the time-varying characteristics of uneven snow distribution on roofs. In order to enhance the understanding of snow distribution on roofs and predict the uneven snow cover more accurately, a method based on the Mixture model considering the evolution of the snowpack profile is proposed. The validation of this research method showed that the numerical simulation agreed well with the experimental results. The method was applied to investigate the accumulation process of snow particles on an arched roof by analyzing the relationship between the deposition and erosion of snow particles and the local bottom surface profile. The wind tunnel test, numerical simulation, and theoretical analysis indicated that under steady snowfall conditions, the snow depth does not increase indefinitely when there is partial snow cover on roof. Finally, the macro mechanism of snowpack evolution was proposed, revealing that the deposition and erosion of snow particles are processes through which the snowpack profile gradually adapts to the wind-snow flow field. © 2025 Elsevier Ltd

Rain-on-snow (ROS) events can significantly increase roof snow loads in buildings, particularly as retained rainwater adds to the snowpack's weight. Recent roof damages from ROS load have been observed in both old and new structures, as climate changes exacerbate such events. Evaluating ROS load in existing snow load codes is crucial to determine whether they adequately address climate-driven impacts, including changing precipitation patterns and extreme weather events. This paper presents a systematic review of the ROS events, damage cases, current methods, and changing climate which shows that snowpack, its properties, and flow type are the key areas of focus. The review of ROS load standards exposed a reliance on historical data and snowpack characteristics, with limited consideration of climate change impacts on ROS surcharge loads. The bibliometric analysis of keywords revealed that environmental factors, snowpack properties, and climate change effects need to be considered for modeling ROS load. Among the available models, snowmelt and snowpack models are effective for long-term ROS simulations, particularly regarding snow depth, density, and pore distribution. In contrast, flow models can provide practical solutions for estimating ROS load while accounting for both uniform and non-uniform wetting front flow conditions in older snowpacks. The distinction between uniform wetting front flow and matrix-preferential flow is pivotal in determining the complexity of ROS load models, as these patterns significantly influence water retention in snow. As global warming can intensify ROS events, reassessment of ROS load standards with climate models is imperative to understand the future effects of climate non-stationarity. © 2025 Elsevier B.V.

Focusing on the design and construction of snow structures, this paper explores the properties of snow materials, construction methods, and operation–maintenance strategies, aiming to demonstrate how to integrate architectural functionality, aesthetics, and structural reliability in snow architecture. It reviews current methods of snow material testing and numerical simulation, yet research on the material properties of machine-made snow remains limited. Current design trends in snow architecture emphasize diverse artistic expressions. After reviewing construction methods of existing snow buildings, the paper employs finite element analysis software to validate design schemes. Upon confirming structural feasibility, it further proposes a monitoring framework for snow structures. © 2025 by the authors.

我国地域广阔,气候复杂,降雪区域覆盖大面积国土。长期降雪天气的密集出现导致雪致工程灾害频发。其中,建筑倒塌由于直接危及人们的生命和财产安全,受到社会的高度关注。究其原因,主要是降雪突增,加之气流作用下形成局部堆雪,超出屋面荷载设计值。大跨空间结构由于屋面结构自重轻、面积大、体型复杂和雪荷载占比大的特点,其设计荷载往往由雪荷载控制,属于雪荷载敏感型结构。遗憾的是我国建筑结构荷载标准主要对简单体型屋面雪荷载分布进行了详细规定,对大跨空间结构屋面雪荷载考虑较少。为完善我国荷载规范在该领域的不足,本文采用数值模拟方法对大跨空间结构屋面积雪分布进行了深入分析和阐述。主要内容如下:1.积雪漂移数值模拟理论与方法改进。积雪漂移数值模拟理论自发展以来先后提出了两种方法:浓度扩散方法和多相流方法。然而这两类方法无法有效还原屋面积雪漂移过程中的风雪双向耦合机制和非平衡发展过程。故本文基于风雪双向耦合的混合流模型,提出了有漂移和无漂移情况下的非平衡态混合流模型。对有漂移情况,通过向雪相连续方程中引入源项来考虑跃移层内雪浓度变化。经验证,改进模型可有效还原非平衡状态下积雪漂移发展过程。对无漂移情况,参考积雪沉积特点,对雪相连续方程和沉积/侵蚀模型进行了修改。经实测验证,改进模型可有效还原飘落雪颗粒的运动轨迹和建筑屋面积雪不均匀分布。2.积雪漂移模拟关键参数研究。基于非平衡态混合流模型,对积雪漂移过程中关键参数的取值及其对积雪漂移的影响进行了分析。雪颗粒密度方面,采用冰密度代替雪颗粒密度会夸大雪颗粒的重力作用,高估近壁面雪浓度;采用基于颗粒随机堆积理论计算得到的雪颗粒密度能更准确地还原近壁面雪浓度和建筑周边积雪分布。雪相粘度方面,通过对比分析证明了流化雪颗粒可简化为牛顿流体进行模拟;雪相粘度对流场和雪场的影响程度则受限于雪浓度。风速方面,通过对比分析进一步证明了改进模型可有效还原积雪漂移的“自平衡机制”,同时指出风速对积雪分布形式起决定作用。3.大跨球壳屋面雪荷载研究。首先,通过与球壳屋面雪荷载风洞试验结果的对比,验证了数值模拟方法对球壳屋面积雪分布预测的有效性。然后,通过不同风速下球壳屋面雪荷载模拟,分析得到三种积雪分布形式:均匀满跨雪荷载、不均匀满跨雪荷载和背风面半跨雪荷载。最后,通过不同矢跨比和跨度条件下球壳屋面积雪分布模拟,明确了屋面外形和尺寸对积雪分布形式的影响,即随着屋面矢跨比的增加,屋面积雪不均匀分布加剧,但荷载值减小;随屋面跨度增加,屋面积雪不均匀分布减弱,但荷载值增大。4.多跨拱形屋面雪荷载研究。首先,通过与多跨拱形屋面风雪运动试验结果的对比,明确了数值模拟方法对多跨拱形屋面积雪分布的预测精度。然后,通过对不同矢跨比和跨数条件下拱形屋面雪荷载模拟,分析了多跨拱形屋面积雪分布的形成机理。最后,通过对多跨拱形屋面雪荷载分布形式的研究,明确了有无阻挡情况下拱形屋面雪荷载的分布形式、跨间波谷处积雪滑落堆积量和多跨拱形屋面雪荷载分布特征。

Given the escalating frequency of extreme cold weather worldwide, snow-induced building failures have increased substantially, especially in large-span space structures. The reason for engineering accidents lies in a lack of understanding of the intricate process of the mechanism of full-period evolution of snow "accumulation-melt-crystallization- accumulation" under the coupling actions of wind, rain, and heat. It is significant to develop a comprehensive and accurate environmental wind tunnel for conducting snow-relevant experiments under the multi-factors, which are barely studied. Hence, this paper proposes and establishes an experimental system called "Simulator of Natural Action of Wind-Rain-Heat-Snow for Space Structures (SNOW)." The system consists of an atmospheric boundary layer cryogenic wind tunnel subsystem, snowfall simulation subsystem, rain simulation subsystem, solar and building heating simulation subsystem, and high-precision multi-task monitoring and control subsystem. The facility can provide a 0–20 m/s stable wind field, −15 °C–0 °C low-temperature conditions, and a 2 m × 2 m experimental section. The calibrations of each subsystem were conducted in SNOW to ensure each component can successfully provide basic conditions for snow-relevant experiments. The SNOW can accurately simulate the entire process of natural snowfall and snow evolution under the coupling effects of wind, rain, and heat. © 2024 Elsevier Ltd

The sliding of roof snow may result in surcharges of snow load on lower roofs or the injury of pedestrians on the ground. It is therefore of great significance to study the mechanism of roof snow sliding, such that prevention or control measures can be developed to manage the risk. Considering four commonly used roofing materials, glass, steel, membrane, and concrete, two types of experiments were carried out in this study to possibly reveal the influence of roofing materials on the shear strength of the roof–snow interface: one is the critical angle tests where the angle at which the snow starts to slide off from the roof is tested, and the other is the shearing tests which aim to test the shear strength of the roof–snow interfaces at specific temperatures. The results showed that the critical angle for roof snow sliding, as well as the shear strength of the roof–snow interface for the four considered roofing materials, show a U-shape trend with the increase in surface roughness and that the shear strength of the roof–snow surface ranges from 0.15 kPa to 2 kPa for the cases considered, while the strength reaches its maximum at certain temperatures near −5 °C for a specific roofing material and snow thickness. These findings could be a useful reference for future experimental or simulation studies on roof snow sliding. © 2024 by the authors.

The typical resolution for long-term wind speed records that are publicly available in China is daily, this is too coarse for a sound analytical simulation of snowdrift on building roofs. Take Harbin, China as an example, an algorithm was proposed in this study to address this issue, where the commonly-used 2-parameter Weibull distribution was applied to fit the distribution of 10-min mean wind speed. A parameter estimation method, which combines the method of moment and cumulative probability, was proposed to estimate the parameters of Weibull distribution using very limited information on wind speed. The fitted probability model was validated using high-resolution wind speed data by comparing the snowdrift estimated by the modeled wind speed and that estimated by the actual wind speed. Finally, an analytical simulation of snowdrift on a flat roof was carried out to illustrate the application of the proposed model, and the probabilistic characteristic of the derived ground-to-roof conversion factors for snow loads were analyzed. It is indicated that the proposed model is easy to implement and provides a good estimation of the snowdrift on building roofs, and the derived conversion factors could be satisfactorily modeled using a Generalized Extreme Value (GEV) distribution or a normal distribution. © 2023 Elsevier Ltd