Preliminary study of the structural role played by masonry infills on RC building performances after the 2011 Lorca, Spain, earthquake

On May 11, 2011 an earthquake of magnitude 5.1 (Mw) struck Murcia region causing 9 casualties and damage to buildings and infrastructures. Even if the main characteristics of the event would classify it as a moderate earthquake, the maximum PGA registered (equal to 0.37g) exceeded significantly the hazard at the site according to local code provisions. The latter is a result of directivity effects in the near source region. An overview of earthquake characteristics and a general study of the damage observed is provided. Finally, an approximate quantitative, large scale, explanation of the damage observed is carried out on the basis of recent literature findings. Notwithstanding the lack of proper structural design characterizing building stock in the area, most of the losses were caused by non-structural damage and, according to in field observations, it seems clear that masonry infills provided additional, “not designed”, strength to reinforced concrete buildings