大跨高墩刚构桥施工环境影响分析及其对策

Construction environment impact analysis and its countermeasures of long-span rigid frame bridge with high pier

考虑温度、风荷载对特大桥施工的影响,对比分析英国规范和中国规范中2种温度梯度模式以及不同横桥向风速情况下的刚构桥施工过程中应力与挠度变化。研究结果表明:特大桥施工过程中应加强温度、风力等环境影响的监控,应选择合适的温度梯度模式来计算和控制施工过程中温度对桥梁立模标高的影响,并在施工过程中进行挠度预补偿;对于峡谷地形,应建立有限元模型分析风力对结构影响,得出允许施工测量及允许施工的风速临界值,并加强墩底应力监测。

Considering the influences of temperature and wind load on the construction proces of long span bridge,comparing the British standard and China standard in two temperature gradient modes,this paper analy-zes the bridge deflection and stress changing caused by different wind speed.The research results show that the environmental impact of monitoring should be strengthened to eliminate into bridge linear deviation in the process of long span bridge construction,such as temperature,wind and so on.Choosing the appropriate temperature gradient model to calculate and control the influence of the model of the bridge during the construction of the in-fluence of elevation,and having deflection precompensation in the process of construction of bridge.In the val-ley,a finite element model should be established to analyze the effect of wind on structure and obtain the value of wind speed that allows construction measurement and allows the construction.At the same time,the wind moni-toring and wind induced at the bottom of the pier stress monitoring should be strengthened.