"Rehabilitation of reinforced concrete school building to improve static and seismic performance"

ABSTRACT: Existing concrete frame buildings often have deficiencies not readily apparent and, hence, theirperformance is poor during earthquakes. Unfortunately, the national code practices for new concrete framebuildings are meaningless when they come to seismic performance of the existing ones, and the methodolo-gies to identify those that are vulnerable to collapse have been not available. The consequence is an inevitable potential catastrophe for some individual buildings during earthquakes. Recently, displacement based meth-odologies have been elaborated, as capacity spectrum method and others, which are more suitable for evaluat-ing the performance of existing buildings. This study dealswith a school concrete frame building in PiazzaArmerina, province of Enna (Italy), built before 1980 according to Italian non seismic code practice and toforce based design. It proposes the seismic assessment and the retrofit design of the building, adopting dis-placement based procedure to estimate the component member forces. This study can be divided into twoparts: i) to find the principal material and structural deficiencies along the inertial forces path from the hori-zontal diaphragms to the foundation systems through joints and connections of the resisting elements; ii) to make the displacement based retrofit design for assessment of the school building, avoiding localized struc-tural changes as the fitting of localized concrete shear walls. The seismic performance is to obtain the base safety objective compatible with the site class C and with the acceleration design response spectrum of zone 2(0.25g PGA) of the Italian code practice.