Negative shear lag effect in box girders with varying depth

A study on negative shear lag effects in box girders with varying depth is performed using a modified finite segment method developed by the writers. Three types of structures-simply supported, cantilever, and continuous box girders-under various loading conditions are considered. The investigation unveils some unique features of the positive as well as negative shear lag phenomenon in box girders with varying depth. In particular, it is found that the variation of the midspan section height to support section height ratio (h/H) has the most significant influence on the negative shear lag effect. The study also finds that the negative shear lag not only exists in cantilever and continuous box girders but also in simply supported box girders with varying depth.