Analytical Estimation of Economic Loss for Buildings in the Area Struck by the 1999 Athens Earthquake and Comparison with Statistical Repair Costs

Reliable loss assessment (in monetary terms) for buildings struck by an earthquake is an essential factor in the development of seismic risk scenarios for a given urban area. The evaluation of loss due to building damage in a certain region depends both on seismic hazard and the vulnerability of the building stock in the area. The study presented herein consists of predicting the loss to selected groups of buildings struck by the 1999 Athens earthquake using an analytical methodology and comparison with statistical repair costs collected after the earthquake. Since no near-field strong ground motion recordings from the main shock were available, a pilot methodology was used for its analytical evaluation for different soil conditions. Different suites of motions were derived, based on various theoretical and semi-empirical approaches, and were then used in analytical investigations of the seismic behavior of the buildings in the examined area, aiming at the prediction of economic losses. An in-situ survey of about 10% of the total building stock was performed, and data regarding the structural type, actual earthquake damage, and corresponding repair costs were collected. The statistically derived repair cost for the area was compared with the economic loss estimation obtained using the analytical procedure and various estimates of the seismic action in the area considered, and was found to agree with it reasonably for some of the seismic hazard scenarios.