1,721,020 research outputs found
Empirical estimate of fundamental frequencies and relevant damping for Italian building
No full textThe aim of this work is to estimate the fundamental translational frequencies and relative damping of a large number of existing buildings, performing ambient vibration measurements. The first part of the work is devoted to the comparison of the results obtained with microtremor measurements with those obtained from earthquake recordings using four different techniques: horizontal-to-vertical spectral ratio, standard spectral ratio, non-parametric damping analysis (NonPaDAn) and half bandwidth method. We recorded local earthquakes on a five floors reinforced concrete building with a pair of accelerometers located on the ground and on top floor, and then collected microtremors at the same location of the accelerometers. The agreement between the results obtained with microtremors and earthquakes has encouraged extending ambient noise measurements to a large number of buildings. We analysed the data with the abovementioned methods to obtain the two main translational frequencies in orthogonal directions and their relative damping for 80 buildings in the urban areas of Potenza and Senigallia (Italy). The frequencies determined with different techniques are in good agreement. We do not have the same satisfactory results
for the estimates of damping: the NonPaDAn provides estimates that are less dispersed and grouped around values that appear to be more realistic. Finally, we have compared the measured frequencies with other experimental results and theoretical models. Our results confirm, as reported by previous authors,
that the theoretical period–height relationships overestimate the experimental data
Seismic waves generated by oscillating buildings: analysis of a release test
No full textA three-stories, base-isolated building located in Rapolla (Potenza, Italy) was tested with a snap-back experiment. Free-field measures were performed using 3D seismometers, located at 10 and 50 m from the buildings in direction of motion and at 10 m from the building in direction transverse to the motion. At each measurement point it was possible to separate the soil amplification effects from two source terms, due to the base-isolated building and to the reaction block. The ground motion was noticeable: at 10 m in the longitudinal direction it was comparable with a small size, near-field earthquake
Indagini speditive sulle caratteristiche dinamiche degli edifici in c.a. a supporto di valutazioni del comportamento strutturale
No full textEffect of a single vibrating building on free-field ground motion: numerical and experimental evidences
No full textIn situ measurements of site effects and building dynamic behaviour related to damage observed during the 9/9/1998 earthquake in Southern Italy
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Ambient noise measurements to support emergency seismic microzonation: the Abruzzo 2009 earthquake experience
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