Design of Additional Dissipative Structures for Seismic Retro-fitting of Existing Buildings

Abstract: This paper presents an innovative approach for improving the seismic protection of existing structures by introducing an additional dissipative structure (ADS). The seismic energy impacting the building can be dissipated through the contribution provided by the ADS, thereby reducing the need for the existing building to ensure its own seismic capacity. This retrofitting technique is well-suited for structures facing architectural restrictions or challenging-to-update elements. It can help address foundation issues by applying loads to new external components. This paper describes the design of the ADS and proposes a displacementbased design procedure. The design process involves a non-linear static analysis and a simple procedure that must be iteratively repeated until the retrofitting target is achieved. This approach is simple and computationally efficient and can also be used for complex and irregular structures. Such structures are frequently encountered, and existing structures often exhibit unusual geometries and materials requiring extensive numerical modeling. The efficacy of the technique was evaluated using two case studies involving a school building and a hospital located in central Italy. The results of numerical analyses indicated that owing to the ADS’s contribution, the seismic capacity of both the buildings was enhanced, addressing the challenges associated with complex foundation interventions.