Abstract：The old communities whose main buildings were constructed according to the old codes have been in service for more than ten years, so they shall be more vulnerable than the new communities. Therefore, it is very necessary to assess and improve the resilience of old buildings in order to build more resilient community. In this work, the assessment and improvement on the resilience of old buildings is divided into three stages: pre-disaster preparation stage, disaster response stage and post-disaster recovery stage. In the pre-disaster preparation stage, the initial functionality goal of old community, which can be further decomposed into the functionality goals of old buildings by using the event tree analysis method, is established. Next, the initial functionality of old buildings is evaluated to judge whether the initial functionality goal meets the requirement. For old buildings without meeting the initial functionality goal, the particle swarm optimization method is adopted to optimize the functionality of buildings before disaster. In the stage of disaster response, the Monte Carlo simulation method is used to evaluate the functionality loss. In the post-disaster recovery stage, the function of functionality recovery of old buildings is proposed. Finally, the resilience of retrofitted and un-retrofitted old buildings is evaluated respectively based on the analysis of the functionality changes in the three stages. By comparing the results of resilience, the improvements of the resilience of old buildings are analyzed. Particularly, based on a case study, the proposed framework for resilience assessment and improvement of old community is implemented and demonstrated. Furthermore, the case study indicates that the proposed framework can provide the decision maker the retrofitted goal of infrastructure in old community and the improvement degree of community resilience before disaster.
