Seismic protection of Heritage structures through Vibrating Barriers

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Historic structures in seismic prone areas are extremely vulnerable. The main reason is that such structures have not been properly designed to withstand earthquakes and also because the construction materials deteriorate with the time. The most recent earthquakes, such as the one in Norcia 2016 are clear examples manifesting the necessity to act promptly to protect heritage structures from such natural disaster. Seismic protection of heritage structures is an unresolved research problem that not only is a public safety issue but also adds to the constraints for preserve the artistic value of heritage buildings. In this regard, there is a clear gap in the knowledge that leads to the research question on how it is possible to protect a structure without modifying it. Previous research suggests that protecting structures by seismic action is managed using localised solutions such as isolators and dampers. Research also shows that one main reason is that the introduction of control devices in existing structures is too invasive, costly and requires the demolishing of some structural and/or non-structural component. For heritage structures clearly such technologies cannot be applied and therefore no seismic protection actions are currently taken to protect such artistic treasures. Research has yet to examine the potential of non-invasive devices for protecting heritage structures. The proposed research will investigate for the first time the use of the novel vibrating barriers (ViBa) to reduce seismic vibrations of heritage structures. Vibrating barriers (ViBa) are massive structures hosted in the soil and tuned to reduce the vibrations of neighbourhood structures through a structure-soil-structure interaction mechanism. As the ViBa is detached from the structure it is particularly suitable for heritage structures so to entirely preserve their original structure without any alteration. The proposed research will aim to establish a general methodology to protect heritage structures through a project that tests the role of ViBa and unknown design parameters. Technical details will be developed through a case study recommended by the cultural partners. In particular the design of the ViBa will require first the numerical modelling of the heritage structure and the soil underneath through a finite element approach. In this regard the cultural partners will provide the data to establish a realistic model of the heritage structure. The ViBa will be then designed through an equivalent discrete model based on the traditional Winkler approach. Moreover, the optimization of the installation of ViBa will be explored with the industrial partner to make this technology cost-efficient.Research questions1) What are optimal ViBa design parameters and how are determined?2) What is the sensitivity of the ViBa design parameters to the model uncertainties?3) Will the ViBa be a cost-effective solution?