Urban societies depend heavily on the proper functioning of infrastructure systems such as electric power, gas, potable water, and transportation networks. Normally invisible, this reliance becomes painfully evident when infrastructure systems fail during disasters. Moreover, because of the network properties of infrastructures, damage in one location can disrupt service in an extensive geographic area. The societal disruption caused by infrastructure failures is therefore disproportionately high in relation to actual physical damage. As a result of the project, new retrofitting strategies will be developed to improve the resilience of infrastructures to withstand natural hazards. The project aims to improve the resiliency of buildings, bridges, and communities in general through new advanced technologies such as base isolations, viscous dampers, etc. Base isolation systems that are able to control the shape of the floor response spectrum will be analyzed, in particular their behavior under vertical excitations. Attention will be given to infrastructural systems’ components and then it will be extended to performance of component assemblages (e.g., bridges, pipeline networks, etc.). The project will range from field work of specific lifeline damage in New Zealand, Japan and Italy after the earthquakes to laboratory simulations done in the laboratory of the University of California at Berkeley with scaled models and numerical analyses. Complexities of infrastructures, which include societal as well as technical issues will be addressed in the project. The project will try to answer through an interdisciplinary approach to the following questions: How, for instance, will the failure of one bridge affect businesses throughout the urban area that rely on the transportation system? How will the failure of one infrastructure system disrupt other infrastructure systems? How can repairs following a disaster be planned so they minimize social and economic losses?