火灾对施工中系杆拱桥混凝土箱梁性能的影响分析

Analysis on the Effect of the Fire on the Tied-Arch Bridge in the Concrete Box Girder

为了研究系杆拱桥火灾后混凝土和箱梁损伤程度的大小和性能的变化,针对火灾后一座1~64 m系杆拱桥的过火结构进行检测和分析,并现场取样对火灾过程中混凝土箱梁温度场、混凝土受损程度、火灾后混凝土微观结构等进行实验分析,得到系杆拱桥在遭受火灾后各项性能的变化,为桥梁火灾检测提供一种可靠的的检测方案和检测依据,得到高温后混凝土性能变化,同时建立该桥的有限元模型,模拟得到的火灾后系杆拱桥承载力及变形等性能的变化情况和实测结果基本一致,为桥梁火灾后受损情况鉴定提供了一种可行的有限元模拟方法。

In order to test the fire structure of one bridge on 1-64 m arc bridge for studying the damage degree of the arc bridge after the fire and its changes of the performance. Thus we got various performance changes of the arc bridge and did some sampling test after the fire. Analysis of the temperature field,concrete damage,microstructure of concrete after fire. In order to establish finite element model of the bridge,the result showed that the changes of the performance in arc bridge after the fire keeps consistent with the measured results. Our work provides a reliable detection scheme and the basis for bridge fire detection and shows a feasible method of finite element simulation for identification of bridge after fire damage.