Seismic protection of masonry buildings by means of a reactivated epdm-fiber reinforced elastomeric isolation system

Masonry is widely known as a structure with high vulnerability to horizontal loads. This study investigates the possibility of improving the seismic performance of existing masonry churches using reactivated EPDM (ethylene propylene diene terpolymer) rubber formed as an unbonded fibre reinforced elastomeric isolator (UFREI) type application. Such recycled material can reduce the production cost of the isolation system. Experimental tests are performed to characterize the mechanical properties of the reactivated EPDM. In series, detailed three-dimensional (3D) finite element (FE) models are used to characterize the behaviour of UFREIs. An Abaqus User Element (UEL) is developed to simulate the 3D behaviour of UFREIs for large scale seismic analyses of complex isolated structures. The results of cyclic shear analyses show that the proposed UEL model can accurately predict the UFREI’s behaviour. A series of non-linear dynamic analyses are performed to investigate the seismic response of an historical masonry church in the original and base-isolated configurations employing UFREIs. Numerical results show that the fixed-base model of the church experiences severe and widespread damage, while UFREI is found to be effective in significantly reducing the damage level of the church when subjected to moderate-to-high seismic actions. Moreover, it can be observed that the isolator satisfies the maximum lateral displacement requirements.