Integrated measurement techniques for the monitoring of the ancient walls of Ferrara

The ancient walls surrounding the historic center of Ferrara for 9 km almost uninterrupted, create one of the most impressive defensive systems of the Middle Ages and the Renaissance. The earthquakes of May 2012 increased the instability of the bastion of “Sant’Antonio” in the south walls, in fact, existing lesions are evidently grown. In order to preserve this historical and artistic heritage a complex monitoring system, based on the integration of various surveying techniques was realized. At the base of the structure a high precision geometric leveling network has been materialized to determine the vertical component of displacements, indeed on the top have been set up targets to determine by total station the planimetric component of displacements. Finally, we used TLS (Terrestrial Laser Scanner) to rate global variations of wall shape and some crack gauges to monitoring the main lesions. From the first repetitions of surveying with the described techniques, we remark a progressive increase of the framework deformation and an interesting agreement of the results.