Dynamic Characterization Test of the New Law Court in Naples

The New Law Court in Naples, Italy is a group of buildings where all the law activities of the city are conducted. Load tests on the structure were required for the final acceptance of the purchaser after the construction was complete. Given the particular type and shape of the structure, traditional load tests were not possible so it was decided: (1) to conduct a dynamic test of the structure; (2) to analyze its dynamic behavior; and (3) to verify its seismic reliability. The investigation focused on the skylight of the central portion of the building complex, formed by steel frames supported by a concrete structure. The structural behavior was quite complex. Frequencies associated with both the global modal shapes of the whole structure (which were often coupled themselves) and the local resonances of single members were identified. The seismic test showed a non-negligible reduction of the first structural frequency when increasing the level of stress. This behavior is related to the contribution given by the nonstructural components which cannot be neglected, when service stresses are low. The structural characterization allowed the calibration of the finite-element model, whose dynamic characteristics were very close to the experimental ones.