Method for calculating cracking bending moment and flexural capacity of fabricated concrete-filled steel tube combined truss girder under action of hogging moment

The invention discloses a method for calculating cracking bending moment and flexural capacity of a fabricated concrete-filled steel tube combined truss girder under the action of hogging moment, and belongs to the technical field of bridge engineering. The method comprises the following steps: determining design parameters of the concrete filled steel tube combined truss girder; the fulcrum section curvature phi and the section cracking bending moment M in the negative bending area are calculated; and calculating the flexural capacity Mu of the negative bending area according to the normal section strain distribution and the internal force balance relationship. The theoretical calculation value obtained through the method is well matched with the test value, the cracking bending moment and the flexural capacity of the fabricated concrete-filled steel tube combined truss girder bridge under the action of the hogging moment can be rapidly and accurately obtained, and the calculation efficiency and accuracy of