Recent study pays attention to the seismic resistance of ancient monuments

The Archaeological News Network reports that recent study conducted by Constatinos Spirakos and his team noted that monuments and other historical constructions in Greece are in great need of better earthquake protection.

Spirakos is both a professor in the department of Civil Engineering at the National and Technical University of Athens and a Director of the Laboratory of Earthquake Engineering. His interdisciplinary research program 'Thales–NTUA SEISMO' consists of experts in civil and chemical engineering, architecture, geology, and archaeology. It is aimed precisely at developing a comprehensive methodology for evaluating the seismic behavior of Greek monuments. Evaluation lends to appropriate intervention, depending on the seismicity of each area. He is currently researching various monuments to check how they will believe under seismic duress.

Modern scientists are unsure if the ancient Hellenes build their monuments with earthquakes in mind. Obviously, many monuments have survived to the modern day, but many of them had to be rebuilt over the centuries—either in Hellenic times or Roman times or even later. The fact is, however, that these monuments were rebuilt and from that point on, they stayed rebuilt. Their main structure survived despite decades of neglect. As such, it stands to reason that in ancient Hellas and many neighboring regions, the inhabitants were able to recognize which building techniques and materials offered strength against seismic shocks, and were able to adopt new and effective earthquake safe styles of construction. Spirakos acknowledges this:

“Many ancient monuments such as the Acropolis have very good seismic behavior and have proven it over time. When a monument remains over time it has either never faced a very strong earthquake, or it has sufficient durability. But in the future there might be stronger earthquakes. If a building, either contemporary or historical, has remained standing until now, it does not necessarily mean that it will last into the future. We want to intervene with historical structures and make them capable of withstanding a possible stronger earthquake. It is important that a monument is monitored continuously over time. Experiments in the laboratory have shown that the ancient vertebrate columns have excellent behavior in earthquakes. The ancient Greeks developed and applied architectural rules which have been proved timeless many of which are still applied today".

It is important to note that modern renovations to monuments have often led to a decrease in seismic resistance. The Parthenon, for example, was restored in the beginning of the 1900’s. the iron clamps and dowels used were not resistant to corrosion, nor covered by lead that protected them from corrosion and provided them with plasticity. This ignorance and disregard of the techniques of the ancient builders had and have important consequences for the monument, including leaving it more vulnerable to seismic activity.

Related studies to that of Spirakos have been made on two representative monuments in Athens, the Temple of Hephaestus–Thissio (5th century BC) and the Monastery of Kaisariani (11th-12th century AD), where a monitoring system with six instruments which will record the seismic tremors will be installed. Later on, the Laboratory of Earthquake Engineering of NTUA will be doing experiments on monument simulations in order to control their reactions to a possible future earthquake and propose ways to improve their seismic behavior.