Learning from Failure: Long-term Behaviour of Heavy Masonry Structures

On March 17 1989, the Civic Tower of Pavia collapsed without any apparent warning sign, killing four people. After an experimental and analytical investigation lasting nine months, the collapse cause was found in progressive damage dating back many years and due mainly to the heavy dead load put on top of the existing medieval tower when realising a massive bell-tower in granite. Other case histories have been collected: the collapse of the St. Marco bell-tower in Venice in 1902; the Sancta Maria Magdalena bell-tower in 1992 in Dusseldorf; the damages to the bell-tower of the Monza Cathedral; and to the Torrazzo in Cremona. Later on, in 1996 the collapse of the Noto Cathedral showed that similar progressive damages can take place in pillars of churches and cathedrals.The experimental research aimed to show the reliability of this interpretation went on and it is still continuing since 1989 and it is described in the book. After a careful interpretation of the experimental results, also based on experiences from rock mechanics and concrete, the modelling of the phenomenon for massive structures as creep behaviour of masonry was implemented.The book has the scope of helping architects and engineers to deal with the continuous damage of heavy structures and, to understand the signs of the phenomenon while proposing some modelling, but also to give guidelines for the on site investigation, monitoring and repairing of the damaged structures.

Table of Contents:
Chapter 1: Failures due to long-term behaviour of heavy structuresIntroduction; The collapse of the Civic Tower of Pavia: search for the cause; Long-term behaviour of masonry structures; Collapse and damage of towers due to long-term heavy loads; The role of investigation on the interpretation of the damage causes; Comparison between the two towers; ConclusionsChapter 2: Experimental researches into long-term behaviour of historical masonryIntroduction; Tests on the masonry of the Civic Tower of Pavia; Tests on the masonry of the crypt of the Cathedral of Monza; CommentsChapter 3: Collapse prediction and creep effectsIntroduction; Short-term compression: failure analysis and collapse prediction using numerical simulations; Long-term compression: experimental assessment; Conclusions and future workChapter 4: Effects of creep on new masonry structuresIntroduction; The step-by-step in time approach to modeling time-dependent effects; Case 1: An axially loaded column; Case 2: Composite structural element subject to bending; New mathematical approaches to modeling creep; Discussion; ConclusionsChapter 5: Experimental study on the damaged pillars of the Noto CathedralIntroduction; The collapse and the decision for reconstruction; On-site investigation on the remaining parts of the collapsed pillarsChapter 6: Monitoring of long-term damage in long-span masonry constructionsIntroduction; Monitoring and long-term damage; Role of monitoring in the study of ancient constructions; Monitoring: methodology and requirements; Measuring damage and deformation related to historical or long-term processes; Structural modelling and monitoring; Case studies; ConclusionsChapter 7: Modelling of the long-term behaviour of historical masonry towersIntroduction; A continuum damage model for masonry creep; Structural analyses of two masonry towers; Remarks and future perspectivesChapter 8: Repair techniques and long-term damage of massive structuresIntroduction; The bed reinforcement technique; The experimental campaigns; Case studies; Final remarksChapter 9: Simple checks to prevent the collapse of heavy historical structures and residual life prevision through a probabilistic modelIntroduction; The safety of ancient towers; A probabilistic model for the assessment of historic buildings; Fragility curves from the experimental data; Application to the bell-tower of Monza; Conclusions