The debate on the strengthening of two slender masonry structures in early XX century: a contribution to the history of wind engineering

In thispaper,thedebatesandthestudiescarriedoutinthe first halfoftheXXcenturyonthedynamic response oftwoslendermasonrystructurestowindactionsarepresented.ThetwobuildingsaretheSt. Gaudenzio BasilicainNovaraandtheMoleAntonellianainTurin,bothdesignedbytheItalianArchitect Alessandro AntonelliattheendofXIXcentury.Theirexceptionalaudacity(121and167.5mhigh, respectively)raisedmanydoubtsontheirstructuralsafety,leadingbetween1930and1954tomany consolidation interventions.InthecaseofSt.Gaudenzio,theseworksapparentlyproducednewdamage, in animpressivesequenceoffailureandinterventions.Forthisreason,aheateddebateconcerningthe dynamic responseofthestructuretowindactionwasarousedbetween1939and1942.Inthecaseof Mole Antonelliana,windactionwasonlymarginallyconsidereduntilthecollapseofthespirein1953, but itsreconstructionwasundertakenthroughanumberofexperimentaltestscarriedoutinthewind tunnel oftheAeronauticsLaboratoryofTurinPolytechnicin1954.Theseexperimentswereamongthe first pioneeringwindtunneltestsoncivilstructuresinEurope.