Posted: 2018-01-14

Incheon bridge model

Keywords: civil engineering, 3d printing, cable stayed, flexible deck

Incheon Bridge with it's 800m long main span is a civil engineering marvel.

Figure 1. Incheon Bridge

Some basic specs of the bridge:

  • Total length - 21.38km
  • Span lengths - 80m, 260m, 800m, 260m, 80m
  • Pylon height - 230.5m
  • Construction beginning - 2005
  • Construction finish - 2009

Wouldn't it be neat to make a scaled down model of it?

Goal

Design and manufacture one of the pylons with symmetrical cable stayed sections. The model should look good, be easy to manufacture and have some degree of resemblance to the real structure.

Design and manufacturing

Inspiration

Although having reference photos is helpful, we are primary focused on the aesthetics of the model, not it's faithfulness to reality.

Figure 2. Model art piece (Incheon Bridge by Lee Gyurim 2017)

Manufacturing

Based on the measurements from the reference painting (Figure 2.), wiki data and a bit of guess work I ended up scaling the model down about 1550 times with a 15cm high pylon and a 33cm long symmetrical span. The complete model then 3d printed in PLA.

Figure 3. 3d printing model's bridge deck

Assembly

The model was split into pieces, a base plate with the foundation and vessel collision prevention facilities; 3 piece deck, and a single pylon. The pylon is connected with the base by 2 M3 flat-head screws. The deck floats on the main pylon's cross beam. Due to the manufacturing limitations, and replacement material properties, the deck is stiff enough to support itself. The cables were made from thread and anchored to the deck with CA glue.

Figure 4. One-sided slope

Figure 5. Inward slope

The way in which the cables were anchored allows for regulation of the deck slope (Figure 4. and 5.)

Results

Figure 6. Gray Incheon Bridge model

Figure 7. Red Incheon Bridge model

Figure 8. Incheon Bridge models

DB