The use of passive seismic protection in structural rehabilitation

摘要

In the recent years, many technologies of seismic protection have been developed in an attempt to mitigate the effects of earthquakes on buildings or other structures. The most important examples of seismic protection technology are the base isolation and the use of energy dissipators. A great majority of applications of this type of seismic protection had been done in new structures, and there are already a significant number of examples of the use of these technologies in seismic rehabilitation all over the world. In this paper, the analyses of the different types of seismic passive protection and their possibilities of use in structural rehabilitation is presented. The rehabilitation of structures from the old masonry historic buildings to more recent reinforced concrete buildings is discussed. Two studies of seismic rehabilitation with passive protection are presented. The first study is the rehabilitation of an old masonry lighthouse ('Farol dos Capelinhos', Azores) using base isolation. This structure had been affected by an earthquake and volcano eruption and needed to be reinforced. One of the studied solutions was the use of seismic base isolation at the base of the Lighthouse tower. This study and its results are presented in the paper. The second study is the rehabilitation of an old masonry building with the use of viscous dampers. This building is an example of an important part of the existing building stock of Lisbon, commonly designated by 'Gaioleiros'. This type of buildings were constructed in the period between the end of the 19th century and the start of the 20th century, and are composed of exterior masonry walls with wood infill panels and wooden floors. This kind of structures are particularly vulnerable to the seismic action and are objects of different studies for possible retrofit interventions.