It used to connect the panel from first row and second row.

For connecting the trusses of the first and second row. For dual-row single-deck design, install one brace horizontally on the superface center of each truss (or Reinforced chord member). For dual-row dual-deck design, besides one brace installed on the superface, one more brace should be installed on the rear end montant of the upper truss (one also installed on the front end montant of the first truss. For triple-row bridge, the position and number of brace to be installed shall be the same as dual-row bridge. While installing, put the four hollow sleeves on both ends into the brace holes on the two trusses, and then fasten with bracing bolts and nuts.

There are some kinds of supporting frame.

321type:
1.450 supporting frame(1270mm*540mm*80mm)
 

2.900 supporting frame(1270mm*990mm*80mm)

200type:
1.Vertical supporting frame(1764mm*544mm),

2.horizontal supporting frame(2366mm*560mm),

3.wide vertical supporting frame(1764mm*794mm),

4 wide horizontal supporting frame(2366mm*810mm).