Traffic Light Poles

Figure 1 shows two traffic light poles.

Traffic light poles.
Two different traffic light poles structures

Structures 1 and 2 consist of half-portal frames; structure 1 includes a stay cable. The blue arrow indicates the vertical displacement direction of the frames free-ends, assuming that both structures are equal except for the stay cable unit of structure 1.

  • Can the stay cable of structure 1 have a big influence of the free-end vertical displacement?
    Can the stay cable affect the global stability?
    How does the wind affect the structures?
  • Figure 2 shows a schematic lateral view of structure 1 and a variant with a rigid block.

    Traffic light poles.
    Structure 1 Rigid block variant
    Schematic structural drawing of two traffic light poles

    The red arrows (F1 and F2) represent forces, assuming that both structures are equal except for the rigid block and F1 = F2.

  • Is the free-end vertical displacement v1 = v2?
    What are the main parameters that affect the vertical displacement of both structures?
  • Supposing that the traffic lights are carried by a portal frame, as shown in figure 3.

    Portal frame.
    Portal-frame traffic light pole structure
  • Can the relationship between material use and vertical displacement be reduced by using a portal frame?
    What are the main structural and constructive differences between a half-portal frame and a portal frame?