Suitability of Optical Fibre Sensors and Accelerographs for the Multi-disciplinary Monitoring of a Historically Complex Site: The Case of the Acropolis Circuit Wall and Hill

The purpose of the current study is the investigation of the suitability of optical fibre sensors and accelerographs for the multi-disciplinary monitoring of historically complex sites, focusing on the Acropolis Circuit Wall and Hill. The Acropolis of Athens is the most outstanding ancient Greek monumental complex still existing in our time, with the most well known monuments being the Parthenon, the Erechtheion, the Propylaia and the Arrephorion. Among the standing monuments of the Acropolis Hill, the Circuit Wall functions as a gravity wall, retaining poorly compacted backfill that covers the inclined bedrock, and has suffered over the years various types of loading, leading to structural damages. The historical significance, the complexity of the geomorphological conditions in the region and the vulnerability of the archaeological site to natural and man-made hazards has led over the last years to the application of various contemporary technologies on it. In this framework and aiming to the investigation of the structural integrity of the Circuit Wall and the Acropolis Hill, multi-disciplinarily monitoring has been included, via optical fibre sensors and accelerographs. More specifically, an optical fibre array has been developed on the Circuit Wall of the Acropolis Hill, continuously transmitting data since June 2016 to date. Furthermore, 10 high-quality broadband accelerographs have been installed over the last decade on specific locations on the Hill, recording in continuous mode on 24-bit digitizers and transmitting data in real time. In the current paper the monitoring arrays are presented and characteristic recordings are shown and discussed.