Analysis of the Influence of Atriums in Seismic Performance of RC Primary School Buildings

Spanish primary school buildings are likely to present a high seismic vulnerability. This is due to two main factors: (a) most of them were built prior to the enforcement of the Spanish seismic codes; (b) the elevated child-to-adult ratio compromises the effectivity of the evacuation plans. In this work, the schools of the Spanish province of Huelva, mainly reinforced concrete framed buildings from the 70s, were studied. First, a general classification based on the structural type and overall geometry of the building was made. Next, several characteristics of the buildings that could influence their seismic response have been analysed through a sensitivity analysis. This paper focuses on one of the characteristics studied: the existence of an atrium (an observed recurrent irregularity) and its position. Different versions of the index building model, varying the position of the atrium, have been analysed. Non-linear static analyses were used to study the seismic performance of the models. Results have shown that if the atrium is located in the short direction of the building, it improves its seismic performance, in most of the cases. However, the addition of one or more atriums in the long direction of the building diminishes the global strength of the building. Finally, it should be mentioned that torsional effects appear when the atrium is not located next to the centre or the surface occupied by the atrium is large. Therefore, the existence and position of the atrium must be carefully considered for a safe seismic design.