Seismic Upgrading of Existing Stone-Masonry Buildings: Lessons from the Earthquake of Bovec of 1998

On the basis of extensive experimental and analytical research in seismic behaviour of existing stone and brick masonry buildings, carried out in the last decades, methods for seismic upgrading have been developed and verified. The interventions, based on the tying of the walls at floor levels, replacing the existing wooden floors with r.c. slabs, and strengthening the walls with cement-grouting, have been first used on a large scale in the Soca River Valley after the earthquakes of Friuli of 1976. When analysing the damage to buildings, caused by the earthquake of Bovec, which affected the same region in 1998, it has been found that houses, damaged in 1976, but strengthened afterwards according to recommendations issued in 1976, resisted the earthquake of 1998 without significant damage.