Seismic assessment of pombalino Buildings

Abstract

Portuguese Pombalino masonry buildings were built mainly in Lisbon after the 1755s Lisbon Earthquake. These buildings are characterized by a mixed timber-masonry structure, known as the gaiola pombalina (cage), and were built aiming to withstand the horizontal seismic loads. The cage is composed of timber floors and improved mixed timber-masonry shear walls (“frontal” walls). It was arguably the first case in history of an entire town built with the purpose of providing seismic resistance to its buildings. In this paper, a description of the Pombalino buildings is presented, GIS mapping tool was developed to identify the main features of Pombalino buildings in Lisbon downtown area and the results of the seismic assessment of existing building are briefly discussed. A three-dimensional model was developed in Tremuri program based on the equivalent frame model approach. The building was modelled using non-linear beams for masonry panels. The “frontal” walls were modelled by a macro-element model developed and calibrated according to an experimental campaign. The seismic assessment of the global response of the building was determined through non-linear static (pushover) analyses. Due to the fact that building does not fulfil the safety requirements for the ultimate limit state, a strengthening solution was proposed in order to improve the seismic behavior of the building.