Hybrid tensioning light prefabricated small box girder structure

The utility model discloses a mixed tensioning light prefabricated small box girder structure. A small box girder comprises a top plate, a web plate and a bottom plate. The web plate and the bottom plate are both of a span medium-thickness structure; the bottom plate is provided with a steel strand; the steel strands are linearly arranged and are constructed by adopting a pre-tensioning method process; the web is provided with a plurality of slow-bonding steel strands; the projection of each retard-bonded steel strand on the vertical face of the corresponding web is arranged in a curve mode and anchored to the beam end of the corresponding beam; the diameter of each retard-bonded steel strand is larger than that of the steel strand, and a post-tensioning process is adopted for construction. The construction method comprises the following steps: 1, prefabricating a single beam; 2, erecting a single beam; 3, cast-in-place of inter-beam diaphragm plates; 4, bridge deck slabs between the cast-in-place beams are s