城际铁路与地下道路共构设计大断面方案比选

Comparison of Large Section Schemes of Intercity Railway and Underground Road Co-Structural Design

为合理确定城际铁路与地下道路共构设计时隧道匝道汇入主体结构的大断面方案,采用有限元计算软件Midas Civil分别对平顶顶板、折板形顶板及拱形顶板3种方案进行建模计算,分别对不同方案的位移、应力、弯矩等进行分析。结果表明,拱形顶板与折板形顶板的受力性能均优于平顶顶板,且刚度增大,应力分布合理,弯矩值大幅度减少。综合考虑施工难易程度、工程量等因素,结论是选用折板形式作为隧道与城际铁路合建段大断面的顶板施工方案,具有结构受力合理、施工技术成熟、工程造价可控三大优势。

Finite element software( Midas civil) is used to model and calculate the flat roof,folded roof and arch roof respectively in this paper in order to determine the large section scheme when merging tunnel ramp with the main structure for an integrated design of railway and the underground road. The displacement,stress,bending moment and other aspects are analyzed respectively. The results show that the mechanical properties of arch roof and folded roof are better than that of flat roof. At the same time,the stiffness is increased,the stress distribution is rational and the bending moment value is greatly reduced. A comprehensive consideration of the construction difficulty,work quantity and other factors shows that the folded form selected as the roof of the large section of the joint construction section of the tunnel and the railway has three advantages: reasonable structural stress,mature construction technology and controllable project cost.