Selection Criteria of Experimental Setup for Historical Structures

In numerous countries, the city centers are mainly characterized by the presence of masonry buildings, which in the recent decades have gained a great importance for several reasons. In fact, due to their architectural and historical value, are often adopted for public functions. Moreover, also when they have a private use, such structures may have great prominence for the tourism and economy. As a consequence, an increasing request of preserving such patrimony has been expressed by the society and has given impetus to research activities in this field. One of the most important aspect of this research is the acquisition of detailed information to improve the knowledge level of these structure which affects the accuracy of the subsequent analysis and, thus, the correct design of required interventions. Thus, the proper choice of the investigation techniques represents a key step for the accurate evaluation of the safety level of the structure. Several procedures are available, and the criteria for their optimal selection are still debated. The present paper deals with these issues, by discussing the limits and advantages of several available methods for monitoring of masonry historical structures. To this aim the case study of the bell tower of Trani Cathedral in Apulia (Italy) has been chosen. This structure can be considered as an example of a widespread architectural and historical typology in Italy. An extensive experimental investigation has been performed by adopting three different methods which are here compared and discussed in detail.