The utility model relates to a novel U rib, including U rib body, the bottom plate of U rib body be the arc structure, the pterygoid lamina tip of U rib body inboard or the outside are equipped with the arch, pterygoid lamina and bellied terminal surface be the face of weld that a slope set up, inside horizontal strengthening rib and the vertical strengthening rib of being equipped with respectively of U rib body, horizontal strengthening rib be the U type structure of matcing with U rib body shape, vertical strengthening rib distributes along U rib body length direction, vertically the strengthening rib setting is in horizontal strengthening rib inboard, the utility model has the advantages of reasonable design, having improved the weld structure of U rib with the roof, having made the welding relation more firm, strengthened the structural strength of U rib simultaneously, made its strength increase, the structure is more stable, and life increases.