不同截面形状隧道格栅拱架竖向承载能力对比

Comparison of Vertical Bearing Capacity of Tunnel Grille Arch Frame with Different Cross-section Shapes

为解决不同截面形式的格栅拱架构件竖向承载能力不明确的问题,对4种不同类型的隧道格栅拱架模型进行设计、加工、加载、分析,同时利用ANSYS有限元软件对模型的变形能力以及截面边长、厚度的改变对拱架稳定性的影响进行分析。研究结果表明:1)拱架采用双拱形式比单拱形式更具有良好的力学性能,外立柱比内立柱多分担50%的荷载;2)选择截面边长尺寸为18 mm、厚4 mm的模型,能使材料性能得到充分的利用,进而降低工程造价;3)拱架的变弯点处易发生应力集中,使得喷射混凝土结构更易损坏,必要时应加强监控,并应尽可能地使拱架圆顺、减少连接节点,以减少应力集中。

In order to analyze the vertical bearing capacity of grille arch frame structures with different cross-section shapes,4 different types of tunnel grid arch frame models are designed,processed,loaded and analyzed.Meanwhile,the finite element software ANSYS is used to analyze the deformation ability of the model and the influence of side length and thickness of cross-section on the stability of arch frame.The study results show that:(1)The double-arch form has better mechanical properties than the single arch form,and the outer column shares 50%more load than the inner one.(2)By selecting the model with side length of 18 mm and thickness of 4 mm,the material performance can be fully used and the cost of the project can be reduced.(3)The stress concentration is easy to occur at the bending point of the arch frame,which would easily lead to damage of sprayed concrete,hence,measures such as monitoring strengthening,round arch frame connection node reduction should be adopted.