GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 2.3 459 been performed along the horizontal direction. Mode frequencies were very clear at 4.5 Hz on the N-S direction and 6 Hz on the E-W direction. • CityHall. Thestructure ismorecomplex than the other buildings analyzed: it has two orthogonal sides linked to a stout central body; the highest side has 6 floors. Also in this case two vertical directions have been tested, one for the main central body and the other for the major side of the building. The measure in the horizontal direction has been performed on the second floor and not at the top floor because the other floors were shorter. Many structural modes have been identified: 1.8 Hz and 2 Hz both on the transversal and longitudinal directions (coupled modes), 2.8 Hz on transversal direction and 4 Hz on the longitudinal one. The 1.8 Hz peak might be imputable on the soil-structure interaction or on a rocking mode. • Province building. It has a peculiar shape, similar to a cake-slice. Therefore, the measures have been performed along three verticals, one for each corner of the building. Again, one test has been made on the horizontal direction, with an instrument at each corner at the same floor. This is the only building for which SSR analysis could not be performed, since the building is quite stiff and the HVSR function of the ground floor shows the soil amplification contribution, therefore can not be used as a reference. The structural frequencies identified were at 3.7 Hz (longitudinal) and 4.7 Hz (transverse), clearly visible on vertical 1 and 2, while on vertical 3 the frequencies are still visible on the transversal component but on the longitudinal one are higher, 4 and 5 Hz respectively. • Architecture building – University of Basilicata. The building has a rectangular shape, regular in elevation, with a big internal covered patio. Measurements have been taken along Fig. 3 – Standard spectral ratio (SSR) curve for each floor, referred to the basement in the longitudinal, transversal and vertical components, along vertical 1 (panel a), vertical 2 (panel b) and horizontal (panel c) arrays.