大跨径钢桁架梁整体顶推施工仿真计算分析及与平面分析对比

The simulation and analysis on overall pushing construction of long span steel truss girders compared with plane analysis

对其施工过程进行有限元仿真分析,可以对整个施工过程以及施工过程中关键结构的力学反应形成直观的把握,为顶推力、导梁长度等施工参数确定以及施工工艺和工序的制定提供依据,从而在施工中能够做到有的放矢,实现简化施工、加快施工速度的目的。以青尼罗河大桥钢桁架梁顶推施工为背景,采用三维和平面有限元方法分别进行计算,对两种计算进行了对比。结果表明,顶推施工仿真计算中,最大轴力出现的地方均处在桥墩附近。在没有偏载情况下,空间模型与平面模型相比较,最大拉压轴力分布完全相同,两者的轴力值也相差不大。

The whole construction processing and key structure mechanics reaction can be obtained intuitively by simulating and analyzing the construction process with the finite element method,which provide the basis for determining construction parameters such as pushing force,guide beam length and so on and for formulating construction process and procedure.Thus with a purpose in constructin,goals of simplifying the construction and accelerating the construction speed can be achieved.The steel truss girders pushing construction of the green Nile river bridge as the background,results obtained by with two kinds of calculation methods,that is,3D and 2D finite methods are compared,which shows that maximum axial force always appear near piers in the pushing construction.In no slanting load cases,the distributions of maximum tension and compression axis forces are identical and values of that varies slightly by comparing the space model with plane model.