PSI - Issue 28

M.L. Puppio et al. / Procedia Structural Integrity 28 (2020) 330–343 Puppio M.L. et al/ Structural Integrity Procedia 00 (2020) 000–000

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2.2. Magliano in Toscana On November 13th, 2012, and on December 16th, 2014, two portions of the walls of Magliano in Toscana (GR) collapsed after severe rainfalls. The city walls of Magliano are dated back to the Medieval age even though being partially rebuilt in the mid fifteenth century. They show an articulate plane geometry and a various texture. After the 17th century they lost their defensive function and got less attention in terms of rehabilitation intervention. The first collapse (November 2012) concerned the North-Western bastion. It has a circular shape plane (diameter of 9.0 m -14 m) and a height of about 20 m (Fig. 3). Another failure (December 2014) regarded a linear portion of the Eastern walls. The collapse showed a general poor quality of the masonry. This was made of small and medium size stones in the bottom and, at the top, of a called rubble masonry with an earth filling in the internal core. Artistic restoration works a few months before the collapse did not bring benefit to the structural capacity.

Fig. 3. N-W bastion of Magliano in Toscana before (left) and after (right) the collapse (November 2012).

2.3. Cana di Roccalbegna On October 6th, 2013, the collapse of a portion of 12,5 m affected the medieval walls of Cana di Roccalbegna (GR) as shown in Fig. 4. The collapsed section was about 4.5 m high and 0.5 m wide. Two factors contributed to the collapse: relevant rainfall events before the collapse and low maintenance, though recent restoration works on the surrounding pavement were done. The survey after the collapse showed some cracks adjacent to the collapsed part. Also in this case, the trace of previous failures, together with the presence of florid vegetation around the walls are clear signs of water inside the wall and endemic critical conditions of structural integrity.

Fig. 4. Collapse of urban walls in Cana di Roccalbegna (GR).