Three main truss parabolic edge sections of multi -thread layering iron road bridge structure

Three main truss parabolic edge sections of multi -thread layering iron road bridge structure to adapt to the layering of indisputable road bridge roof beam, heavy requirement well, the mutual noninterference of each circuit operation. Including steel longeron and bridge deck, the section of steel longeron includes the left side purlin, the right purlin of well purlin and both sides, well purlin face perpendicular to horizontal plane, and the left side purlin, the slope of the right purlin face form three purlins and fall the parabolic edge section. The bridge deck is including setting up the upper deck of bridge system and the lower floor bridge deck of setting in steel longeron bottom surface at steel longeron top surface.