钢管混凝土拱肋管冷系统的参数敏感性分析

Parameter Sensitivity Analysis of Cooling Pipe System of Steel Tube Concrete Arch Rib

以成贵铁路西溪河大桥的钢管混凝土拱肋为研究对象,建立了部分拱肋的三维实体模型.在拱肋钢管及腹板外侧布置环型冷却水管用以降低钢管混凝土的温度差及温度应力.通过改变冷却水管管径、水管间距、通水温度等参数,分析这些参数对观测点温度及温度应力的影响.结果表明:钢管混凝土的温度随着冷却水管间距减小而减小,当间距在0.6 m时,再减小冷却水管的间距对钢管混凝土温度的影响就不明显了;在通入25℃的冷却水时,钢管混凝土沿拱肋方向上的温差很小,钢管混凝土的温度应力也较小,当冷却水的温度低于15℃时钢管混凝土的温度应力显著增大.冷却水管的管径对钢管混凝土拱肋的温度改变影响较小,在管径增大1倍时,混凝土的温度改变仅0.5℃.

This research established a three-dimensional solid model of some arch ribs of the concrete filled steel tube arch rib of Xixi River Bridge over Chengdu-Guiyang Railway. The annular cooling water pipe was arranged outside the arch rib steel tube and the web plate to reduce the temperature difference and the temperature stress of the concrete filled steel tube.The influence of the parameters on the temperature and temperature stress of the observation point was analyzed by changing the diameter of the cooling pipe, the spacing of the water pipe and the temperature of the water. The results showed that the concrete temperature decreased as the cooling water pipe＇s spacing decreased; at the distance of 0.6 m, the effect of decreased distance on the temperature of cooling water pipe concrete filled steel tube was not significant; in the 25 ℃ cooling water, the temperature difference along the direction of CFST arch rib was very small; the temperature stress of the concrete filled steel tube was small; when the cooling water temperature was lower than 15 ℃, the steel concrete temperature stress increased significantly. The diameter of the cooling pipe had little influence on the temperature change of the concrete filled steel tube arch rib. When the diameter of the tube was doubled, the temperature change of the concrete was only 0.5 ℃.