PSI - Issue 47

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

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ScienceDirect

Procedia Structural Integrity 47 (2023) 521–534

27th International Conference on Fracture and Structural Integrity (IGF27) Designing the special connectors of the Parthenon’s west tympanon A. Vrouva a,b *, H. Mouzakis a , I. Psycharis a a National Technical University of Athens, School of Civil Engineering, Department of Structural Engineering, Laboratory forEarthquake Engineering, Polytechnic Campus, Heroon Polytechniou9, 15780 Zografou, Greece b Hellenic Ministry of Culture and Sports, Acropolis Restoration Service, Polygnotou 10, 10555 Athens, Greece Abstract The pediment of the Parthenon consists of two parts, unlike other monuments where usually a plain wall is constructed. The first part, which forms the background for the sculptures, is formed with thin marble slabs (orthostates) and the second part is constructed as a simple massive isodomic wall with marble ashlar blocks (backing wall). In the initial construction several connections were provided to unite the two individual parts of the tympanon along with the raking cornice. Those connections are essential as the backing wall acts as a counter weight to the lean orthostates that have a natural tendency to overturn during seismic excitation. The so- called “twisted connectors” were a special feature in the original structure. In the current restoration project where the central part of the west pediment of the Parthenon is being restored the need for the redesign of those connections arose. The redesign had to account for the damages of the monument and meet the standards of safety especially during earthquakes. The most severe damage of the backing wall was provoked by the 2 nd century A.D. fire that caused severe cracking to the inner part of the isodomic wall, though the surface of the blocks seems intact, compromising the mechanical properties of the stone and thus its bearing capacity for about half of the blocks’ width. The construction was modelled using DEM analysis and the models of the structure were calibrated using real accelerograms obtained by the installed accelerometric array. The calibrated model was then used to establish the design forces acting on the connectors between the two parts of the tympanon (i.e. orthostates and backing wall). The seismic events selected were chosen to correspond to the worst case earthquake that could have occurred in Athens in more than 2000 years. The connections proved numerically to be crucial for the behavior of the tympanon and the avoidance of a possible collapse of the central orthostates towards the west. It had been decided that the connections would follow the ancient arrangement, meaning the connectors had to be anchored in the original sockets provided by the original structure. In situ testing of the anchorage scheme of the special connectors was performed in order to test their capacity since their form aimed not only to carry the design loads but also to maintain as much archaeological evidence of the structure intact, with the additional pursuit that the system remained hidden in the core of the marble blocks similar to the original construction, at least for

* Corresponding author. Tel.: +30-694-549-8553. E-mail address: a_vrouva@hotmail.com

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the IGF27 chairpersons

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the IGF27 chairpersons 10.1016/j.prostr.2023.07.072