An Experimental Study on the Strengthening of RC Frames with Soft Storey Irregularities with Different Types of Steel Diagonals

When the loss of life and property is considered, it is clear that special precautions must be taken against the earthquakes among the natural disasters. Post-earthquake observations, especially those made in the developing countries, reveal that there are many reasons for the damage and loss of life, not just one. The formation of soft storey irregularity is one of the most important factors among them. In this study, it is aimed to propose an alternative strengthening method to eliminate the adverse effects of the formation of a soft storey irregularity. Four identical frames with two stories and single span were constructed and tested under reverse cyclic loading which simulates the earthquake. The first frame among them was prepared by bonding bricks as an infill wall on two stories and it was considered to be the reference frame. In the 2nd frame, the formation of soft storey irregularity was facilitated by removing the infill wall on the lower story and the behavioral differences were examined. The remaining two frames were strengthened by using steel elements in two different diagonal shapes on the lower story. As a result, the experimental study showed that the strengthening with steel diagonal elements increased the lateral load-carrying capacity of the frame with soft storey behavior by 250% and the energy dissipation by 120% and also provided better results than the reference frame.