跨海大桥钢箱梁温度场特性分析及降温措施研究

Temperature Field Characteristics and Cooling Measures of Steel Box Girder of Cross-Sea Bridge

为认识和防控温度变化对跨海大桥钢箱梁的影响,通过有限元模拟和现场实测,研究了钢箱梁内部空间空气温度场的时序变化特性;总结了夏季高温条件下的降温措施。结果表明:与无沥青路面相比,有沥青路面的钢箱梁在升温阶段内部空气温度明显更低,甚至低于外界气温,内部空气温度极值出现得更晚且降温更缓慢;靠近顶板的钢箱梁断面竖向温度变化迅速,其余位置温度变化平缓,整个温度梯度可用指数函数和一次函数描述;在钢箱梁内部空气温度较高时,可采用“个体防护+移动式冷风机降温”的综合降温措施。

In order to understand and prevent the adverse effects of temperature changes on the steel box girder of the cross-sea bridge,the time series change characteristics of the air temperature field inside the steel box girder were studied through FEM and field measurement.And reasonable cooling measures for the high temperature condition in summer were proposed.The results show that:compared with the asphalt-free pavement,the internal air temperature of the steel box girder with asphalt pavement will be significantly lower during the heating stage,even lower than atmospheric temperature outside the steel box girder,and the internal air temperature extremes appear later and cool down slower;the vertical temperature of the steel box girder section near the top plate changes rapidly,while the temperature changes at other locations are gentle,and the entire temperature gradient can be described by exponential function and linear function;when the internal air temperature of the steel box girder is relatively high,the comprehensive cooling measures of“personal protection+mobile cooling fan”can be adopted.