THE ASSESSMENT OF THE SEISMIC PERFORMANCE OF THE RC BUILDINGS HAVING ONE OR TWO SOFT-STORIES RETROFITTED WITH GAPPED INCLINED BRACING

Aghabeigi et al. (2015) introduced a new method called gapped inclined bracing (GIB) for retrofitting the old buildings with a first soft-story issue. The basic idea behind this method lies in trying to concentrate the seismic demands at the first story where it plays the role of an isolator story and consequently the rest of the stories are displaced as a rigid mass. The GIB element as it is shown in Figure 1 is a gapped bracing connected to the two sides of the columns of the first story. While the structure is at rest, the gap is open and does not affect the overall performance of the system. However, as the lateral displacement exceeds a critical value the gap is closed and subsequently cooperates in withstanding the lateral and gravitational forces exerted by the upper stories (Beigi, 2014). Since the distance between the column bases and these elements’ joint with the beams are as low as 0.5 m, this system is able to enhance the performance of the structures without wasting much of the usable space between the adjacent columns.This method’s effectiveness in the reduction of the earthquake demands on old RC buildings has been assessed on by Aghabeigi et al. (2014). Moreover, they have also performed the cost-benefit analysis to determine the applicability of this method (Beigi et al., 2016).

کلیدواژه ها:

Soft story ، Seismic performance ، Seismic retrofitting ، Gapped inclined bracing (GIB) ، Seismic loss