The Asinelli Tower is a masonry tower built between the 11th and 12th centuries in Bologna, Italy. It is 97.2 meters tall and leans 1.7 degrees to the west. The cross-section of the walls varies along the height of the tower. Strengthening interventions over the last century included installing steel frames and ties to improve structural integrity. Material testing and a structural health monitoring system were also implemented to characterize the tower's properties and behavior.

1. THE ASINELLI
TOWER
Tutor: Simonetta Baraccani

2. Asinelli Tower: geometry
• Masonry tower built between XI e XII
century
• Total height of 97.20 m
• Inclination of 1.7° (corresponding to a
overhanging of 2.23 m) in the West
direction
Geometry:

3. Asinelli Tower: geometry
• The cross section of the walls varies
along the height of the Tower
• The external walls were built using the
so called “a sacco” technique up to a
height of 59.3 m.
Internal fill
External
layers
Geometry:
BRICK
MASONRY

4. Asinelli Tower: geometry

5. Asinelli Tower: history
• During the last century different strengthening interventions have been
realized:
– masonry consolidation trough substitution of the most damaged bricks and
injections of high strength mortar;
BEFORE AFTER
History:

6. Asinelli Tower: history
– installation of steel frames in order to improve the connection of the two external
layers which compose the “sacco”;
History:

7. Asinelli Tower: history
– Installation of external steel ties in order to provide confinement to the masonry.
History:

8. Asinelli Tower: history
• In the 2011 a SHM system has been installed
History:

9. Material
Young’s
modulus
Em
(MPa)
Compression
strength
fm
(MPa)
Shear
strength
fv,m
(MPa)
Masonry
assemblies
3200 4.0 0.7
Mortar 2000 1.9 n.a.
In situ and laboratory tests were performed in order to characterized the material
properties of the Asinelli tower:
IN SITU TESTS:
 jack deformability tests
 standard and pointing
hardness tests
 LABORATORY TESTS:
 Compression test
 Measurements of density
Material properties:
Asinelli Tower: material
characterization

10. Local mechanisms
Common mechanisms observed in the Towers:
• Overturning of upper
portion of the wall and
portions of the orthogonal
walls
• Overturning of upper
portion of the wall
59.3m
59.3m