PSI - Issue 47

A. Vrouva et al. / Procedia Structural Integrity 47 (2023) 521–534 Vrouva et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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4. Design and testing of the special connectors 4.1. Initial design

It was decided that the connections would follow the ancient arrangement, meaning the connectors had to be anchored in the ancient sockets provided by the original structure. The initial design 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 the west façade of the orthostates. For the backing wall it was already decided due to the heavily damaged core of the blocks that the connectors should be anch ored to the east façade to ensure the counteraction of the wall. The connection that was designed contained two titanium parts connected with a special nut (Fig. 11).

Fig. 11. Schematic design of the designed connectors. The blocks of the tympanon orthostates (in orange- the ancient sockets of the twisted connectors are also depicted) along with a block of the backing wall (in green) bearing the connectors. The transparency allows the view of the connectors with its two parts the one inserted into the orthostate and the other anchored in the backing wall block. The part anchored to the orthostate was an L shaped rod inserted in a drilled hole inside the orthostate (that part was smooth and was secured in place by very good fitting without any mortar – in order not to disturb the ancient sockets) and threaded at one end for the nut to engage. The part that penetrated and was anchored to the backing wall was a simple rod threaded for the nut to engage while the other end had the form of a cut off cone (see Fig. 12) in order to meet the requirements of the least damage to the hosting ancient socket resembling a barrel anchorage with wedges.

Fig. 12. The barrel anchorage and wedges specially designed for the project.

4.2. In situ testing of the connectors In situ testing of the anchorage scheme of the special connectors was performed in the Parthenon’s working site, in order to test their capacity, with the help, loading devices and measurement instruments of the National technical