Numerical simulation of the seismic response of an earthquake damaged URM building

Analysis of the seismic response of unreinforced masonry buildings requires reliable nonlinear models as effective tools for seismic design of new buildings and assessment and improvement of existing ones, with current performance based earthquake assessment also being mainly oriented to the use of nonlinear analysis methods. The behaviour of URM buildings characterised by the occurrence of cracking even at low levels of earthquake demand highlights the need to use nonlinear assessment approaches. It is evident that reliable numerical models are needed for performing such complex analyses, with essential validation and corroboration undertaken using evidence from real damaged buildings that were previously subjected to earthquake induced shaking. Within this context, numerical simulation of the earthquake response of Lancaster House that sustained damage in the 2007 Gisborne earthquake is presented using two detailed models based on the Finite Element and Equivalent Frame modelling approaches. The results obtained from both nonlinear static and dynamic analyses are compared with those computed by an analytical simplified approach which is currently being implemented in the revised version of the 2006 NZSEE Assessment Guidelines.