Modeled in MayaEach piece is exported as obj if you want to rearrange them and fbx version is the entire thing as one. I added a version with and without the metal bolts because the bolts and extra geometry that might be unecssasry for your needs.In the zip file is all the textures for each piece as well as to different 2 different texture sizes, being 2048x2048 and 4096x4096. There is also textures for other applications such as Arnold textures, Blender bsdf textures, Unreal Engine 4 textures and Keyshot textures.
Bridge No Bolts - Verts: 20752, Edges: 41282, Faces: 20616, Tris: 41332, UVs: 27294 / Bridge with Bolts - Verts: 157075, Edges: 308582, Faces: 151836, Tris: 303772, UVs: 163617