不良气象微环境下桥塔横梁覆冰灾害过程模拟

Simulation Analysis of Ice Accretion Process of Tower Crossbeam under Adverse Meteorological Micro-environment Conditions

冬季桥塔横梁坠冰是威胁桥梁交通安全的重大隐患之一,系统分析不良气象微环境下横梁覆冰灾害过程机制,是保证桥梁交通安全的迫切需求。依托FLUENT与FENSAP-ICE软件建立桥塔横梁覆冰数值仿真模型,探讨风速、液态水含量和环境温度等微气象参数对桥塔横梁覆冰灾害演化过程的影响规律。结果表明:所提出的数值仿真方法在明冰及霜冰条件下均具有较高的可行性与准确性;对武汉长江二桥桥塔横梁结冰数值模拟发现,覆冰区域集中分布于横梁迎风侧前缘及上下边缘,整体呈现出“U”形分布特征,是横梁防冰、除冰的重点区域;不良气象微环境是影响横梁结冰形态、分布及覆冰量的重要因素,覆冰形状受风速、液态含水量影响较大,受温度影响较小。

Ice falling from bridge tower beams in winter is one of the major hidden dangers threatening bridge traffic safety.Systematic analysis of the mechanism of beam icing disasters in adverse meteorological microenvironments is an urgent need to ensure bridge traffic safety.Based on FLUENT and FENSAP-ICE software,a numerical simulation model of ice accretion for bridge tower beam was proposed.The effects of micro meteorological parameters such as wind speed,liquid water content and ambient temperature on the evolution process of icing disaster were discussed.Results show that the proposed method has high feasibility and accuracy under both clear ice and frost ice conditions.The numerical simulation of ice accretion of the Second Wuhan Yangtze River Bridge shows that the icing area is concentrated on the leading edge and upper and lower edges of the windward side of the beam,showing a“U”shaped distribution characteristics,which is the key area for anti-icing and de-icing of the beam.The adverse meteorological microenvironment considerably affect the form,distribution and amount of icing on the crossbeam.The ice accretion is greatly affected by wind speed and liquid water content,but is less affected by temperature.