Seismic Retrofitting of Unreinforced Masonry Buildings in Italy

摘要

The Italian heritage building stock is dominated by unreinforced masonrybuildings widespread on the whole territory with rammed earth buildings peculiar ofsome regions. A major effort is given to strengthen or retrofit these buildings in order toimprove their safety under seismic loading as well as to preserve them as memory of theancient art of builders and as constitutive elements of the anthrop-environment. Thispaper describes traditional seismic retrofit interventions adopted in Italy. Theseretrofitting interventions, revised according to the modern technologies, derived fromhistorical concept of aseismic devices (i.e. metallic tie-rods, circumferential tie-rods,buttresses, “diatoni”, wall connections, partial reconstruction of walls) suggested to thebuilders’ crafts by observation of earthquake damage and imposed by the past technicalrules. A good degree of confidence on the feasibility, compatibility and effectiveness ofthese techniques for URM buildings is guaranteed after having been extensively testedduring the centuries. Recently, technical national code-guidelines for the seismic retrofitof existing URM masonry buildings have been prepared with the specific purpose to helppractitioner engineers to implement these solutions.