It was presented the use of virtual column method to the calculation of RC bent frames with columns removed according to the apprasial of a large metallurgical mill building; it was also analyzed the changes in the internal forces and displacement,as well as the effect of virtual column stiffness on the internal forces and displacement of bent frames,using specific methods for determining virtual column sections in virtual column method and the one of how to equate a steel roof truss to a solid web beam.