TESTING OF ANCHOR BARS AT THE GRIMALDINA TOWER IN GENOA

The ongoing restoration, aimed at preserving the tower and enhancing its value and usability, also through the insertion of a metal staircase that will allow a wider public to access it, has recently seen the completion of a series of technical tests that are crucial for the safety and effectiveness of the design solutions adopted.
The project, conceived with a careful eye on the preservation of the existing structure and the integrity of the historic walls, required studies of methodologies and solutions that would minimize the direct impact on the original structures, choosing the least invasive ones. Among these is the use of metal profiles, placed to support the structure of the staircase, which are connected to the walls through plates anchored by bars. Through this system, an attempt was made to avoid possible damage to the original walls of the tower, while maintaining the solidity and safety necessary for the intervention.
Following the calculations carried out, it was decided to test the design data by carrying out shear-tensile tests to directly test the safety of the designed system.

The tests, carried out last week by Foppoli Moretta e Associati, were performed using a cylindrical hydraulic jack, with which a gradual load was applied to the anchor bars with the help of two specifically designed and manufactured plates. This test was performed with a manually operated system equipped with a pressure gauge to monitor the pressure. The load was increased slowly, with a linear increase equal to one tenth of the maximum expected load every minute, until reaching the maximum load, which was kept constant for ten minutes. Subsequently, the load was gradually released.

The objective of these tests was twofold: on the one hand, to verify the shear resistance of the individual anchor bolts; on the other, to test the behavior of the metal profiles, which transfer the load to the masonry, in order to ensure that there are no structural compromises.
In conjunction with these tests, tests were also carried out on the wood of the tower using a resistograph, a device that allows the density of the material to be determined and any areas of degradation or low structural performance to be identified.