The assessment of the seismic behaviour of historic residential buildings and the estimation of their possible losses in the event of an earthquake, is a must for defining strategic mitigation plans to prevent irreplaceable heritage losses. In this study an integrated performance based probabilistic risk assessment methodology is developed. An archival study and a field survey allow to identify architectural and construction characteristics of heritage residential buildings in urban areas and determine realistic structural models. These are analysed by using a limit state approach, coded in the FaMIVE method, considering different construction hypotheses, to produce capacity curves which support the identification of a discrete number of typologies representative of the entire building stock in the area. Their fragility functions are then derived using the modified N2 method. Because of the difficulty in quantifying the expected probable losses in purely economic terms, given the heritage value of these assets, losses are computed in terms of damaged floor surface area and mean damage ratio. These have been obtained through the earthquake loss estimation platform SELENA, considering different possible seismic scenarios. The procedure is applied to masonry residential buildings in Pla del Remei area of Valencia, Spain, built between the end of the 19th Century and the end of the Spanish War (1939). This neighbourhood embodies the cultural values, construction techniques and historic legacy of a new and brief era of modernity, inspired by the new urban theories and architectural styles of Eclecticism and Modernism. Despite Valencia being located in an area of low to moderate seismicity, the results show that the maximum percentage of built damaged area ranges from 5.8 to 11.6% for 475 years return period, increasing to 33.59–51.59% for 975 years return period. The high level of resolution of the study allows mapping and identifying the structures at higher risk and is therefore a valuable tool to support sensitive and targeted retrofitting policies.

ResumenLa evaluación de los escenarios de daño y de pérdidas humanas y materiales es imprescindible para la reducción del riesgo sísmico, incluso en regiones de baja o moderada sismicidad.Se presenta el estudio del riesgo sísmico del distrito residencial del Eixample de Valencia (España), de gran valor histórico y arquitectónico, en el que predominan los edificios de mampostería y donde se encuentra gran parte del patrimonio modernista de la ciudad.Se ha evaluado la vulnerabilidad sísmica con el método del índice de vulnerabilidad [1], se ha determinado la calidad sísmica de la edificación residencial según su tipología estructural, estado de conservación, edad y geometría, y se han identificado los edificios más vulnerables. Posteriormente se han determinado las matrices de probabilidad de daño para escenarios deterministas y probabilistas según la distribución binomial o beta equivalente y, finalmente, mediante un sistema de información geográfica se han elaborado mapas de escenarios de daño, pérdidas y costes, para cada intensidad.Los resultados obtenidos confirman que la vulnerabilidad es elevada y el riesgo sísmico apreciable. Un estudio pormenorizado permitiría mejorar el comportamiento estructural frente a sismo de los edificios del distrito, especialmente si están protegidos, contribuyendo a la reducción de pérdidas humanas y materiales y salvaguardando el patrimonio de la ciudad.Por otra parte, el Plan Especial frente al Riesgo Sísmico en la Comunitat Valenciana, aprobado en 2011, recomienda la elaboración de planes específicos en varios municipios entre los que se encuentra la ciudad de Valencia. Este estudio a pequeña escala puede servir como punto de partida haciéndolo extensivo a toda la ciudad.AbstractThe assessment of damage scenarios and human and material losses is essential for seismic risk reduction, even in regions of low or moderate seismicity.A seismic risk evaluation is carried out in the residential district of Eixample in Valencia (Spain), a district with great historical and architectural value, with predominantly masonry buildings and where most of the modernist heritage of the city is located.Seismic vulnerability has been evaluated following the vulnerability index method [1] obtaining the seismic quality for the residential building stock taking into account the structural typology, maintenance level, age and geometry, and identifying the most vulnerable buildings. Damage probability matrices for deterministic and probabilistic scenarios have subsequently been determined considering a binomial or beta-equivalent probability distribution and, using a geographic information system, scenarios of damage, losses and costs maps have been produced for each earthquake intensity.Results confirm that vulnerability and seismic risk is significant and, therefore, a detailed study will enhance the structural earthquake performance of the buildings in the district, especially if they are protected, helping to reduce human and material losses, and safeguarding the city's heritage.On the other hand, the Special Plan against Earthquake Risk in the Valencia Region, approved in 2011, recommends the development of specific plans in several municipalities including the city of Valencia. This small study can serve as a starting point to be extended to the entire city