高温沥青混合料摊铺时钢桁梁桥温度场分析

Analysis on Temperature Field of Steel Truss Bridge during the Paving of High Temperature Asphalt Mixture

高温沥青混凝土桥面铺装摊铺对钢桥面结构的温度场及其力学响应将造成不可忽略的影响。鉴于钢桁式主梁的应用较多而该方面的研究较缺乏,开展了高温混合料摊铺过程下钢桁式主梁的三维时空温度场及其力学响应分析,建立了以瞬态传热理论为基础的钢桁梁桥FEA模型,分析了2m/min摊铺速度、温度240℃、宽度5m、厚度3.5cm的沥青混合料在钢桁梁桥上层摊铺时的钢桁梁温度场时空分布及其力学响应。研究表明:摊铺后35min,最高温度由初始11℃升至77.09℃,此后的降温速率明显小于升温速率。距离摊铺层最近的顶板温度最高,U肋其次,纵肋与横梁最低。

The paving of high-temperature asphalt concrete bridge deck has a non-negligible impact on the temperature field and mechanical response of the steel bridge deck structure. In view of the many applications of steel truss main girder and the lack of research in this area, this paper analyzed the three-dimensional space-time temperature field and mechanical response of the steel truss main girder in the paving process of the high temperature mixture. A steel truss bridge FEA model based on transient heat transfer theory is established to analyze the time-space distribution and mechanical response of the temperature field of the steel truss beam when an asphalt mixture is being paved on the upper layer of the steel truss bridge with a paving speed of 2 m/min, a temperature of 240℃, a width of 5 m and a thickness of 3.5 cm. Studies have shown that 35 minutes after paving, the maximum temperature rises from the initial 11℃ to 77.09℃, and the subsequent cooling rate is significantly lower than the heating rate. The temperature of the roof nearest to the paving layer is the highest, followed by U-ribs, and longitudinal ribs and beams sequentially.