钢管混凝土系杆拱桥先梁后拱施工控制研究

本文以灵武银西铁路立交特大桥为研究对象,使用Midas Civil对全桥进行空间有限元模拟分析,通过计算该钢管混凝土系杆拱桥在先梁后拱施工中的不同施工阶段及内力组合条件下的结构竖向位移,得到了该桥系梁和拱肋的预拱度计算值;通过施工现场监测及有限元建模分析,对系梁和拱肋在不同施工阶段中的应力值进行实时监测控制。研究结果表明:在施工阶段中,系梁最大压应力为24.1 MPa,最大拉应力为15.5 MPa;拱肋最大压应力为26.4 MPa,最大拉应力为22.3 MPa,均满足设计要求。结合系梁和拱肋的预拱度计算及应力监测,该监控技术能够保证桥梁结构在施工阶段中的内力、挠度及线型的控制,为同类型桥梁的施工监控提供了参考依据。

This paper takes Lingwu Yinxi railway overpass bridge as the research object.Midas Civil was used to simulate the spatial finite element analysis of the bridge.By calculating the vertical displacement of the structure at different construction stages and under the condition of the combination of internal forces,the calculated value of the precamber of the tie beam and the arch rib of the concrete-filled steel tube tied arch bridge is obtained;Through the construction site monitoring and finite element modeling analysis,the stress values of the tie-beam and the arch rib in different construction stages were monitored and controlled in real time.The results show that:In the construction stage,the maximum compressive stress of the tie beam is 23.1 MPa and the maximum tensile stress is 16.4 MPa.The maximum compressive stress of the arch rib is 26.4MPa and the maximum tensile stress is 22.3MPa.All meet the design requirements.Combined with the calculation of precamber of tie beam and arch rib as well as the stress monitoring,the monitoring technology can ensure the control of internal force,deflection and line shape of bridge structure in the construction stage,providing reference for the construction monitoring of the same type of bridge.