General Information
Figure 1 shows a pedestrian suspension bridge.
| Type | Single-span suspension bridge |
| Main span | ≅ 80 m |
| Deck width | ≅ 1.5 m |
| Deck width to main span ratio | ≅ 1:53 |
| Pylon | Reinforced concrete |
| Girder | Steel transverse beam |
Main Cable Anchorage
Figure 2 shows an anchorage.
The two main cables are connected to the front region of the anchor block; two short cables (same type and size as the main cables) are connected to the mid-region of the anchor block and the main cables. Figure 3 shows the connection between the main and the short cables.
The two cables are overlapped and fixed with U-bolt clamps.
Deck
Figure 4 shows the deck.
Over the girders are placed pre-assembled units (red shown) and lateral stringers (LS); the latter are made of rectangular hollow sections. A unit is supported by two girders, while a lateral stringers (LS) is supported by four girders. The units are connected by horizontal bolting and consist of expanded steel gratings (deck), stringers, and floor beams. Figure 5 shows the units before installation.
There are three stingers (1 to 3) and eight floor beams (two external and six internal). Stringers 1 and 3 are made of L-sections, while stringer 2 is made of an L-section and a rectangular hollow section (yellow dashed lines) connected over it; the floor beams are made of rectangular hollow sections. Figure 6 shows a schematic cross-section of the bridge and a non-pre-assembled variant.
The variant consists of three stringers made of rectangular hollow sections and steel grating deck.
Suppose a hardwood deck instead of a steel grating deck. What are the main structural and constructive differences? What are the main pros and cons?
Safety Barrier
Figure 7 shows the bridge.
The safety barrier consists of posts made of rectangular hollow sections, tapered post stiffeners (two per post), handrails, and cables, which are anchored to the pylons. Figure 8 shows a schematic cross-section of the bridge and a safety mash barrier variant.
Which is the barrier system that probably uses fewer resources?
What are some possible reasons to choose the post-cable system instead of the mesh system?
Bottom Cables
Figure 9 shows the main span.
There are two bottom cables; they run horizontally between the girders and are anchored to the pylons. Figure 10 shows a bottom cable.
The bottom cable passes through the holes of the eye bolts used for the hanger-to-girder connection. The pylon anchorage is shown in figure 11.
The bottom cable is vertically and horizontally deviated at the first girder and connected to horizontal rebars of the pylon's bottom cross beam. The bottom cable termination consists of a cable thimble and U-bolt clamps.