Increasing the strength of existing building using steel jacketing in seismic zone

Performance evaluation of structures with reinforced concrete columns retrofitted with steel jacketing

“…I s is the moment of inertia of the steel shape about the elastic neutral axis of the composite section, I sr is the moment of inertia of the reinforcing bars about the elastic neutral axis of the composite section, and I c is the moment of inertia of the concrete section about the elastic neutral axis of the composite section. C 1 is the coefficient for calculation of effective rigidity of an encased composite compression member, computed using equation (5).…”

“…Structural and non-structural damages and poor performance of RC buildings with code non-compliances have been observed after recent earthquakes [3]. Most of these damages haven been evidenced in RC columns with insufficient axial/shear loads capacity given by inadequate longitudinal/transversal reinforcement and dimensions, 90-degree hooks for stirrups at both ends of columns, inadequate detailing in beam-column joint regions, strong-beam and weak-columns, soft stories, weak stories, and poor quality construction [4,5].…”

Influence of axial compression ratio in building columns

“…The breach of actual seismic codes and standards by several existing buildings has been noticed and studied by some authors worldwide (Abou-Elfath et al, 2017;Domínguez et al, 2016;Falcone et al, 2019;López-Almansa et al, 2013;Miano et al, 2022;Quintana Gallo et al, 2022;Requena-Garcia-Cruz et al, 2022;Tena-Colunga et al, 2022), and accordingly, the collapse risk of these buildings against earthquake occurrence (Aboutaha et al, 1999;Alfarah et al, 2020;Pampanin & Akguzel, 2011;Ricci et al, 2011;Singh Rawat, 2017) has also been noticed. Furthermore, there are RC columns in Moment-Resisting Frame (MRF) buildings having such high ACR values that undergo excessive DCR, still for vertical loads, as reported by a recent study (Villar-Salinas et al, 2021).…”

“…For the purpose of retrofitting, the RC columns in MRF buildings with excessive DCR under service loads shall be provided with additional compressive strength as a priority, avoiding eventual demolitions and deformations of the existing structures during retrofitting, to secure the structural integrity and safety (Villar-Salinas et al, 2021). There are diverse retrofitting techniques like the addition of steel bracings (Nateghi-A, 1995), the adding of infill walls (Willam et al, 2010), jacketing with fiber reinforced polymers (FRP) (Abdelkerim et al, 2019;Al-Mahaidi & Kalfat, 2018;Azarm et al, 2017) or steel jacketing (Aboutaha et al, 1999;Islam & Hoque, 2015;Singh Rawat, 2017). However, some methods require axial deformation of columns to fully activate the confinement action (for instance, the jacketing with FRP) or require the construction of additional foundation or space availability, which are not feasible in most of the cases.…”

“…However, some methods require axial deformation of columns to fully activate the confinement action (for instance, the jacketing with FRP) or require the construction of additional foundation or space availability, which are not feasible in most of the cases. The compressive, shear and the monotonic or hysteretic deformation (González Cuevas et al, 2007;Singh Rawat, 2017;) capacity of individual retrofitted RC columns and isolated structures have been studied in the last decades. The retrofitting scheme for columns and joints proposed by Villar-Salinas et al ( 2021) is described in subsection 3.3.2.…”