Region 3

The historic seismic activity of the Alto Alentejo is characterized by large numbers of seismic events, of medium intensity, which can produce small and consistent damage to buildings.

The Historic Centre of Evora was selected as a case study, because of the evidences of the use of seismic-resistant elements. The Historic Centre of Evora is structured through a matrix of medieval origins. The intramural core presents a consolidated fabric, organized in compact blocks, consisting of long buildings arranged in a transversal form. The main facades can integrate stone circulation arcades, on the ground floor, thus better reinforcing the block.

The use of other reinforcing elements, such as counter-arches, buttresses or reinforced plinths, enhances the structural performance, at the level of the entire block.
Évora has buildings with an urban character of between 3 and 4 storeys, with rectangular floor plans, narrow and elongated. The buildings are positioned transversely and have gable roofs. The ground floor is clearly distinct from the upper floors.

The main facades present a vertical alignment in the placing of openings, ranging from French doors or windows to chest high casement windows, ripping significantly the facade plan. In the other facades, the openings are less frequent, smaller and are irregulary positioned. The inner partitioning is varied and irregular, and the larger compartments are generally adjacent to the main facade.

The lower floors are constructed in stone-cut masonry and vaulted ceiling, with a reinforced section of the exterior support columns, resembling buttresses. The upper floors are constructed in stone masonry, with the occasional inclusion of interior walls, transversal
to the building plan. Tie-rods are frequently observed, usually located in the upper level floors and at the corners of buildings.

Identified reinforcement elements