Steel box girder with differential strength

PURPOSE: A strength differential steel box girder is provided to reduce the lowering by improving the section strength of a pier part and an abutment part and applying the differential strength. CONSTITUTION: A strength differential steel box girder is composed of an abutment part, a pier part, and a span part. The abutment part comprises a first space(300), second spaces(400,400'), and a third space(500) in which filler is respectively filled. Two or more cut holes(111) are formed in the pier part. The pier part comprises a first space and a second space in which filler is respectively filled. The first space is formed by longitudinally installing a lower horizontal reinforcement plate(140) in the inside lower part of an outer box. An upper plate(110), a lower plate(120), and left and right wall plates(130,130') are combined to the outer box by welding. Vertical reinforcement plates(160,160') are longitudinally installed at both side upper parts of the lower horizontal reinforcement plate in the third space.