1. First prepare eight pieces of paper and scotch tape, the length and width of the paper should be the same, and tear two pieces from the middle to make four pieces;

2. Make the picture below with four smaller pieces of torn paper, that is, roll it up and try to roll it as tightly as possible;

3. Make two strips with two large paper rolls, which are actually a little longer than the first four, and should be rolled tightly.

4. Fold a large piece of paper into the shape shown in the figure below, like a channel steel, with one centimeter on each side;

5. Fold four strips in half, then clip the folded strips on the strips, add two small ones to each strip, and then fix them with transparent tape;

6. Place the two strips in parallel, then put the grooved origami on it as the bridge deck and fix it with adhesive tape;