Abstract
A developed form of the PC box girders using corrugated steel web are flourishingly under construction. The form has been used for the continuous girders and the usage to be developed even for the cable stayed bridges. Since the corrugated web does not possess rigidity along the span axis, the influence due to shear deformation strongly appears. The authors have developed an elastic equation extending beam-bending theory considering shear deformation. The dual three-moment method and the CWB (Corrugated Web Beam) matrix displacements-method are formularized. The obtained knowledge is so important that the practical bridge engineers should take it into their consideration.