Analysis of Cantilever Decks of Thin‐Walled Box Girder Bridges

A spline finite strip approach is presented to analyze the cantilever deck of single‐cell box girder bridges. The effects of distortion of a thin‐walled box section are taken into account by treating the cantilever deck as a cantilever slab with horizontally distributed spring support along the cantilever root. Perspex model tests have been conducted in the model structural laboratory at Tong Ji University. The results based on the spline finite strip method are compared with those of a perspex model test. Simplified solutions are also given for the distribution of transverse moment along the cantilever root, satisfying the following essential conditions: (1) For a given loading condition, the moment at root has a peak value; (2) the area under the transverse moment curve plotted for a given distance c is P ⋅ c; and (3) moment approaches zero as longitudinal ordinate y tends to infinity. Further, sagging moment is detected exactly in the region where the concentrated load is applied. This moment, particularly in the case of long cantilever decks, cannot be ignored in routine design work.