The Effect of RC Core on Rehabilitation of Tubular Structures

In the recent years, there have been many new skyscrapers built which soar into new heights. The most efficient building system for high-rises has been the framed tube system. However, the framed tube buildings suffer from shear lag effect which causes a nonlinear distribution of axial stresses along the face of the building. In the present study, the effect of core on shear lag phenomenon in tubular structures is investigated. Three different tubular structure models including model without core, model with central core and model with central core but eliminated in last 15 stories have been analyzed. A shear lag index is defined for evaluating these models. From examination of the results, the effective influence of core for improving the behavior of framed-tube structures has been concluded. The influence of core in reduction of shear lag in first story is estimated by 5%. Investigating the shear lag phenomenon of columns on web frame, it could be revealed that in top story the positive and negative shear lag phenomena have been occurred simultaneously.