1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Application of modern seismic design codes in everyday practice imposes a need for the seismic retrofit of existing structures, which represents a challenging task when it comes to old masonry buildings. Many of such buildings were built long before design codes, not just seismic ones, and in many cases their structural performances do not conform with the current design criteria. Seismic response of existing masonry buildings, especially public ones, has a strong impact on the society, and therefore deserves a proper attention.
There is a constant need for an improvement of the seismic capacity of old masonry building structures. One of such examples is presented in this paper, which deals with the seismic retrofit of an existing grammar school masonry building in Novi Sad, Serbia. The building was built about eighty years ago, before any design codes. It consists of a basement, ground floor and two upper floors. Structural walls were constructed by using solid bricks without reinforcement, and ribbed floor slabs were made out of reinforced concrete. During the on-site inspections no vertical confining elements were observed, and only some horizontal confining elements were found at floor levels. What makes the retrofit project special is the fact that a new storey is planned to be built upon the existing top storey in order to expand the school’s capacity, which has further complicated the analysis and design.
This paper presents the most important properties of the considered masonry building, the results of nonlinear static (pushover) analyses performed on a spatial mathematical model of the structure with the additional storey, and the applied retrofit solutions used to achieve the necessary seismic capacity with the respect to the provisions of Eurocode 8.