This design is for the bridge design of K4 Road +340 ~ K5+134 section of the viaduct in the west section of Dalian. The project adopts the design of three-hole and one-joint prestressed continuous box girder, and the span of the bridge is 30m +30 m +30 m, with two-way four lanes, which meets the current conditions. The construction bridge under the rear axle can meet the two-way eight-lane traffic conditions. Design calculation includes linear design, overall design and substructure calculation. Using MIDAS, the overall design software of the bridge, the internal force is controlled by program calculation or manual calculation, and then the size of steel bars is put forward line by line to check the bearing capacity, and the stress of key sections and prestressed steel bars are checked. The internal force of the substructure is calculated by program, and the longitudinal line of the bridge is taken as the combination of internal force and displacement after control, and the support on the pier, reinforced concrete pile and bearing capacity are selected for checking calculation. This design has completed the design and calculation of a prestressed box girder bridge, and the design is true and reliable.

Keywords: continuous beam bridge; Box; steel reinforced concrete