分类： 地球科学 >> 地理学 提交时间： 2023-08-15 合作期刊: 《干旱区科学》
摘要： Railways built in cold, snowy, and lightly populated areas are subjected to wind and snow disasters. In this study, we selected a snow hazard prevention and control section of the AltayZhundong Railway in Xinjiang Uygur Autonomous Region of China as the research object. We investigated the deposited snowfall variation characteristics on the two sides and in the embankment pavement area of snow fences with different porosities, fence heights, and arrangement distances using single-factor tests and orthogonal tests based on global atmospheric reanalysis climate data, field survey data, and a multi-phase flow analysis model. The results showed significant differences in the characteristics of snow cover distribution and snow cover thickness between the embankment and the cutting in the absence of snow protection measures. The maximum snow cover thickness of the embankment pavement decreased by 12.6% relative to the cutting pavement. The snow cover thickness of the embankment exhibited an increasing trend from windward shoulder to leeward shoulder, whereas the snow cover thickness of the cutting presented a declining trend from windward shoulder to leeward toe. In the collaborative prevention and control of snow fences and embankments, the three factors can be ranked in terms of their sensitivity to deposited snowfall within the influence scope of snow fences as follows: fence height>arrangement distance>porosity. At the same time, fence height yielded a significant relationship for the influence scope of snow fences (Pfence height>arrangement distance. For the embankment protection of the AltayZhundong Railway against wind and snow, snow fence with a porosity of 75%, a fence height of 4.8 m, and an arrangement distance from the embankment of 60 m produced the best snow control effect. By revealing the characteristics of snow cover distribution along railway subgrade and the protective effect of snow fences, this study provides valuable references for the engineering applications of railway construction in areas prone to wind and snow disasters.
分类： 地球科学 >> 地理学 提交时间： 2022-10-14 合作期刊: 《干旱区科学》
摘要： Guardrail, an important highway traffic safety facility, is mainly used to prevent vehicles from accidentally driving off the road and to ensure driving safety. Desert highway guardrails hinder the movement of wind-blown sand, resulting in the decline of sand transportation by the pavement and the deposition of sand gains on the pavement, and endangering traffic safety. To reveal the influence of guardrails on sand transportation of desert highway pavement, we tested the flow field and sand transport volume distribution around the concrete, W-beam, and cable guardrails under different wind velocities through wind tunnel simulation. Wind velocity attenuation coefficients, sand transportation quantity, and sand transportation efficiency are used to measure sand transportation of highway pavement. The results show that the sand transportation of highway pavement was closely related to the zoning characteristics of flow field and variation of wind velocity around the guardrails. The flow field of the concrete guardrail was divided into deceleration, acceleration, and vortex zones. The interaction between the W-beam guardrail and wind-blown sand was similar to that of lower wind deflector. Behind and under the plates, there were the vortex zone and acceleration zone, respectively. The acceleration zone was conducive to transporting sand on the pavement. The cable guardrail only caused wind velocity variability within the height range of guardrail, and there was no sand deposition on the highway pavement. When the cable, W-beam, and concrete guardrails were used, the total transportation quantities on the highway pavement were 423.53, 415.74, and 136.53 g/min, respectively, and sand transportation efficiencies were 99.31%, 91.25%, and 12.84%, respectively. From the perspective of effective sand transportation on the pavement, the cable guardrail should be preferred as a desert highway guardrail, followed by the W-beam guardrail, and the concrete guardrail is unsuitable. The study results provide theoretical basis for the optimal design of desert highway guardrails and the prevention of wind-blown sand disasters on the highway pavement.
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