TY - JOUR
T1 - Seismic reassessment of the leaning tower of Pisa
T2 - Dynamic monitoring, site response, and SSI
AU - Fiorentino, Gabriele
AU - Quaranta, Giuseppe
AU - Mylonakis, George
AU - Lavorato, Davide
AU - Pagliaroli, Alessandro
AU - Carlucci, Giorgia
AU - Sabetta, Fabio
AU - Monica, Giuseppe Della
AU - Lanzo, Giuseppe
AU - Aprile, Victoria
AU - Marano, Giuseppe Carlo
AU - Briseghella, Bruno
AU - Monti, Giorgio
AU - Squeglia, Nunziante
AU - Bartelletti, Raffaello
AU - Nuti, Camillo
N1 - Funding Information:
The study at hand was funded by Opera della Primaziale Pisana and coordinated by Camillo Nuti. Special thanks are due to Luca Sanpaolesi for his comments and suggestions. Giuseppe Quaranta and Giorgio Monti also acknowledge the support of Sapienza University of Rome through the project “Smart Solutions for the Assessment of Structures in Seismic Areas.” The authors would also like to thank Istituto Nazionale di Geofisica e Vulcanologia of Rome (Giuliano Milana) for providing the equipment for the 2-D geophysical array. The authors also benefitted from discussions with Professors Eduardo Kausel and Carlo Lai.
Publisher Copyright:
© 2019, Earthquake Engineering Research Institute.
PY - 2019/5
Y1 - 2019/5
N2 - The Tower of Pisa survived several strong earthquakes undamaged over the last 650 years, despite its leaning and limited strength and ductility. No credible explanation for its remarkable seismic performance exists to date. A reassessment of this unique case history in light of new seismological, geological, structural, and geotechnical information is reported, aiming to address this question. The following topics are discussed: (1) dynamic structural identification based on recorded earthquake data; (2) geophysical site characterization using a two-dimensional array; (3) seismic hazard and site response analysis considering horizontal and vertical motions; and (4) soil-structure interaction (SSI) analysis calibrated using lab and field data. A substantial shift in natural period, from about 0.35 s to over 1 s (a threefold increase, the largest known for a building of that height) caused by SSI, a wave parameter (1∕σ) of about 0.3, and a minor effect of vertical ground motion are identified and may explain the lack of earthquake damage on the Tower. Recommendations for future research, including the need to establish a seismic bedrock deeper than 500 m, are provided.
AB - The Tower of Pisa survived several strong earthquakes undamaged over the last 650 years, despite its leaning and limited strength and ductility. No credible explanation for its remarkable seismic performance exists to date. A reassessment of this unique case history in light of new seismological, geological, structural, and geotechnical information is reported, aiming to address this question. The following topics are discussed: (1) dynamic structural identification based on recorded earthquake data; (2) geophysical site characterization using a two-dimensional array; (3) seismic hazard and site response analysis considering horizontal and vertical motions; and (4) soil-structure interaction (SSI) analysis calibrated using lab and field data. A substantial shift in natural period, from about 0.35 s to over 1 s (a threefold increase, the largest known for a building of that height) caused by SSI, a wave parameter (1∕σ) of about 0.3, and a minor effect of vertical ground motion are identified and may explain the lack of earthquake damage on the Tower. Recommendations for future research, including the need to establish a seismic bedrock deeper than 500 m, are provided.
UR - http://www.scopus.com/inward/record.url?scp=85065846831&partnerID=8YFLogxK
U2 - 10.1193/021518EQS037M
DO - 10.1193/021518EQS037M
M3 - Article
AN - SCOPUS:85065846831
SN - 8755-2930
VL - 35
SP - 703
EP - 736
JO - Earthquake Spectra
JF - Earthquake Spectra
IS - 2
ER -
