The human losses around the world from earthquakes are mostly common due to the collapse of dwellings thus the low capacity against lateral loads does not give time for people to escape.
In developing countries like Peru, the informality to build dwellings in urban areas is increasing. In Lima city, new emerging districts with no urban planning policy are under development. The main structural system is confined masonry of clay bricks. However, many people live in non-engineered dwellings (wrong materials, irregularities, bad soil conditions, etc.). Damages in this kind of structures by the last earthquakes showed us their high vulnerability.
In order to contribute to mitigate the impact of future earthquakes, appropriate measures to protect human life should be taken into account therefore the assessment of vulnerability must be an important issue. This study proposes fragility functions for typical two-story confined masonry dwellings made of tubular clay bricks. One of those is un-retrofitted and another is retrofitted by wire mesh and plaster mortar. The study also evaluates the effect of retrofitting.
The fragility curves showed 50% of probability that the un-retrofit dwelling will get collapse damage from 300cm/s2 of PGA unlike the retrofitted dwelling from 650cm/s2. Also the un-retrofit dwelling suggests that smaller increment in strong ground motion will result in higher probability of damage, which is reduced by the improvement of retrofitting of wire mesh ‘and plaster mortar.