Vertical-bending properties of composite box girder with corrugated steel web and steel bottom slab

A composite box girder with corrugated steel webs and a steel bottom slab is a new type of steel–concrete structure that works primarily in the vertical-bending state. This study proposes a method to derive the governing differential equations and natural boundary conditions that define the additional deflection induced by the shear-lag effect as the generalised displacement. Two shear-lag longitudinal warping displacement difference functions were set for the cantilever and flange slabs of the box girder to accurately analyse its mechanical properties. The proposed equations are verified by experimental and numerical data. This equations reflect the vertical-bending mechanical properties of the composite box girder, including the non-uniform distribution of normal stress in the flange slabs and the influence of the accordion effect, shear lag, and self-equilibrium conditions.