FRIBAS database: collection of the main characteristics of 313 reinforced concrete and masonry buildings

FRIBAS-DB is a database that comprises information about 312 buildings (237 reinforced concrete moment resisting frame, 71 unreinforced masonry, 4 mixed type). For each building 37 parameters related to the main building characteristics (age, height, structural typology and main vibrational period), and foundation soil characteristics (e.g. resonance frequency, outcropping geology, seismic soil class, topographic class) are reported. The 312 buildings are located in Basilicata and Friuli Venezia Giulia regions (Southern and North-eastern Italy, respectively) and in different geological and built-environment settings. The FRIBAS-DB allows studying the influence of these parameters for the building dynamic response.

In the following the details of each field of the FRIBAS-DB are given.

ID_GIS: unique identifier for each building;

ID: building identifier containing a number and the province acronym (MT=Matera; PZ=Potenza; VdA=Villa d’Agri; FVG=Friuli Venezia Giulia);

Municipality: name of the municipality;

COD_COM: municipality code according to the national institute of statistics (ISTAT);

LAT, LONG: coordinates of the building in the WGS84-UTM - zone 33N (EPSG:32633);

Construction material: RC for Reinforced Concrete Moment Resisting Frame; Masonry for unreinforced masonry buildings; Mixed refers to buildings with both reinforced concrete and load-bearing masonry elements;

Soft storey: presence of a soft storey, i.e. a floor that can activate a weak-floor failure mechanism;

Building use: Residential, Public, Industrial, Turistic;

Age of Construction: < 1919; <1988*; 1919-1945; 1946-1961; 1962-1971; 1972-1975; 1976-1981; 1982-1991; 1992-1996; 1992-2001; 1997-2001; 2002-2008; >2008; (*a more accurate class attribution has not been possible);

# Floors: the last floor was included when its estimated volume was comparable with the those of other floors in the building;

Presence of basement: all the floors that are partially or totally below ground are considered as basement;

Building height from the ground to the top of the roof (m): if the building is located on a slope, the ground floor is considered to be the one at the higher side of the slope;

Building height from the basement to the top of the roof (m): total height, including also the basement and the structures present at the top of the building; 

Building width B (m): the shorter dimension of a circumscribing polygon;

Building length L (m): the longer dimension of a circumscribing polygon;

B/L: ratio between building width and building length as a measure for regularity in plan;

B/H: ratio between building width and building height (from the ground level to the top of the building);

Floor area (m2): the building area calculated based on building footprints (e.g. from openstreetmaps or available national/regional digital maps);

Polygon area (m2): the area of the circumscribing polygon;

Area ratio: ratio between floor and polygon area

Building shape: geometric shape of the building, R (rectangle), S (square), T (T-shape), L (L-shape), C (C-shape), H (H-shape), Tr (trapezoid);

Seismic provisions (masonry): Description of any seismic provisions (e.g. additional pillars, ring beam, walls reinforcement, tie-rods) if present;

Masonry openings (%): percentage of openings with respect to the building lateral surface;

Masonry type: type of load-bearing masonry, including material (e.g. stone, bricks, concrete blocks), layout (regular, irregular) and quality;

Slab: rigid or flexible, rigid floors often consist of reinforced concrete and hollow tiles;

Roof type: wood (with or without hollow tiles), reinforced concrete (with or without hollow tiles);

Additional floors: added afterwards to the building, but not included in the original project;

Foundation type: shallow or deep;

Position of the building: single block is for buildings that consist of a single unit; in case of multiple blocks (e.g. in the case of attached buildings), we distinguish between internal buildings (attached to two or more buildings) and buildings located at the edge (far end blocks attached only to one building). The presence of seismic joints or staircases is specified in the text field;

F1_building (Hz): the experimental fundamental frequencies in two directions of the buildings (longitudinal and transversal) were considered, defined as F1_building (lower value) and as F2_buildings (higher value). The fundamental vibrational frequencies for all buildings have been estimated from single station ambient noise measurements analysed through the Horizontal-to-Vertical Spectral Ratio technique. The noise was recorded at the top of each building, aligning the horizontal axes of the sensor parallel to the two main building axes. Measurements were carried out using two different instruments (Tromino and Lunitek Sentinel GEO). The recording time varies between 10 and 30 minutes. The HVSRs have been estimated by the following procedure: each component was divided into non-overlapping windows of 20 s; each window was detrended, tapered (set to 0.5), padded, Fast Fourier Transformed and smoothed with triangular windows with a width equal to 5% of the central frequency. For each of the 20 s windows, the arithmetic mean of the two horizontal component’s spectra was used to combine E-W and N-S components in the single horizontal (H) spectrum; then the HVSR is computed. Finally, the average HVSR spectrum is obtained, providing also the relative ± 2 standard deviations. 

F2_building (Hz): see above

F0_ Foundation Soil (Hz): the main resonance frequency obtained from HVSR analysis of single station ambient noise measurements. Measurements were carried out using two different instruments, Tromino or Reftek datalogger equipped with Lennartz 3D-Lite. The recording time varies between 10 and 30 minutes. For data analysis see “F1_building (Hz)” field. For some cases, the HVSR from microzonation studies were used;

Geology: the geological classification was inferred from field surveys or the detailed geological maps of microzonation studies at the scale of 1:5000 or 1:10.000, if available. Otherwise the geological map at the scale 1:50.000 was considered. The outcropping geology classes present are: Gravina Calcarenite (coarse-grained carbonate sandstone); Calcari M.te Viggiano (Limestones and carbonate sandstones); Marsicovetere Breccia (massive calcareous breccias); Subappennine clay; Conglomeratic deposits; Sands and sandstones; Clean Gravels; Silts and Clays; Sand; Silty Gravels; Gravels and Sands, with silt and clay; Alluvial deposits; Colluvial deposits; Eluvial and colluvial deposits; Anthropic deposits;

Soft soil/rigid soil: soils with Vs > 360 m/s have been considered as rigid soil. This class is composed mainly by outcropping bedrock (limestones, sandstones and breccias of the South-Appennine Units) and by clean coarse gravels of the Upper Friulian Plain. Soils with Vs < 360 m/s have been considered as soft soils. These are loose sediments (silts, clays, sands, gravels and their mixture) of different origin (alluvial, colluvial, eluvial or antropic).

Seismic soil class: this soil classification refers to the national building code (NTC2018, § 3.2.2) based on Vs30. Vs profiles have been measured nearby the studied buildings. If deduced by microzonation studies, they are marked by star (*).

Topographic class: The topographic class refers to the national building code classification (NTC2018, § 3.2.2).