Investigation of the Characteristics of the Portuguese Moment-frame RC Building Stock

The computation of fragility models can be carried out using post-earthquake damage data or through the development of numerical models capable of reliably representing the structural behaviour of a given building typology when subjected to a set of ground motion records. In Portugal, due to the lack of data regarding groundshaking damage, analytical methodologies are often followed to evaluate the structural vulnerability of the existing building stock. However, these methodologies require advanced knowledge about the geometric and material characteristics of the building typologies, which is often not available or poorly characterized. In this study, the material and geometric properties of the RC buildings, which represent approximately 50% of the Portuguese building stock, were thoroughly analysed. In order to do so, 400 drawings and design specifications from real buildings were gathered throughout the country, in cooperation with private practitioners, design offices and public institutions. For each building drawing, the main frames in the structure that would resist eventual lateral loads were chosen in order to measure the following set of geometric parameters: ground story and upper storeys heights, column widths and depths, beam lengths, widths and depths, and slab thicknesses. The distribution of each geometric property was modelled considering several probabilistic distributions (normal, lognormal, exponential, gamma, beta), and their statistical parameters were derived using the maximum likelihood approach. These results can be used for numerical analysis, thus allowing a better understanding of the physical vulnerability of the RC building stock in Portugal.