Post-earthquake reconstruction: A study on the factors influencing demolition decisions after 2009 L'Aquila earthquake

The evaluation of building reparability after damaging earthquakes is a complex issue, involving factors such as the damage state, residual capacity and post-earthquake safety, initial performance level with respect to design earthquake and repair and retrofit costs. In the post-earthquake reconstruction process after the 2009 L'Aquila earthquake, the funding request had to be accompanied by a detailed assessment of repair costs, the pre-earthquake safety level with respect to new building standard (%NBS) and, if needed, by a detailed design of retrofit intervention and costs. The paper examines the database of severely damaged buildings after L'Aquila, collecting information of repair and retrofit costs as well as the final decision on reparability or demolition and reconstruction; 122 out of 472 severely damaged RC buildings were demolished. It illustrates the most important factors influencing demolition decisions for Reinforced Concrete (RC) buildings. A logistic regression is performed to estimate the probability of demolition pdem for building typologies. Considering pre-earthquake information, the construction age is the most influential parameter, with older buildings having a higher pdem. Another significant parameter is %NBS. Considering post-earthquake information, the repair cost is expectedly the most important parameter. It results that pdem can be expressed as a function of construction age, %NBS and repair costs. A case study illustrates the possible application of the results for a town district in Campania Region, southern Italy.