“两阶段”分析法对大跨钢管桁架屋盖设计影响研究

Effect Research on Designing Long-span Steel Roofs with Tube Trusses by "Two-stage" Analysis Method

对于大跨钢管桁架屋盖,一般的设计计算方法是基于结构采用原位散拼施工。但实际施工时往往采用提升、滑移等更为高效的安装方法。不同的施工方法可能改变屋盖在自重作用下受力体系,在结构中产生内力重分布。这种内力重分布在施工过程结束后可能仍然存在,从而对结构在运营阶段的力学行为产生影响,甚至使结构处于不安全状态。屋盖安装过程分析可以保证结构在施工阶段的受力安全,但不能确保结构在运营阶段结构的力学行为达到设计预期。因此,本文提出了大跨钢结构屋盖的“两阶段(施工阶段和运营阶段)”分析法,并以某高铁客站为研究背景,对采用分块提升安装的大跨度正交空间管桁架结构受力性能进行了研究。通过分析可知,该方法可以让结构在施工阶段和运营阶段的受力情况均处于安全可控状态。

For large-span steel truss roofs, the traditional design method is based on the in-situ assembling. But more efficient methods such as lifting and slipping are often used in actual construction. Different construction methods may change the force system of the roofs under self-weight and produce internal force redistribution in the structure. This internal force redistribution may still exist after the completion of the construction process, which may affect the mechanical behavior of the structure during the service stage, and even make the structure unsafe. The analysis on installing roofs can ensure the safety of the structure during the construction stage, but it cannot ensure that the mechanical behavior of the structure meets the design expectations in the service stage. So, a utwo-stage(the construction stage and the service stage)” analysis method for the assembling of steel structure roofs is proposed. Taking a railway station as the research background, the mechanical behavior of long-span orthogonal spatial tube trusses which is assembled with partitioned lifting has been studied. According to the analysis results, the method can keep the structure in a safe and controllable state during the construction stage and the service stage.