Masonry creep influence on the lateral displacement capacity of slender structures: a case-study of a tank-tower in Italy

Historical constructions were typically designed to be gravity-loads resistant. In the case of masonry towers, relevant structural weaknesses are related to the (axial and lateral) displacement capacity. In fact, the masonry is strongly affected by creep which generates both the axial shortening and stiffness softening. Therefore, the lateral displacement capacity may vary significantly during the time. Since towers are attended to be long-term preserved, it is reasonable to evaluate the seismic vulnerability by also considering the creep’s influence. To make preliminary evidence, a case-study is herein presented referring to a 1-century-old (masonry) tank-tower located in Italy. In fact, even if the conventional seismic capacity’s check, in term of maximum lateral displacement (according to the Italian Desing Guidelines), is satisfied at the present age, the same evaluation referring to future ages (