A marvel of engineering, a jewel of our country, i...

A marvel of engineering, a jewel of our country, is worth visiting all at least once in your life .... !!!! A few words about the construction from the page of the company BRIDGE .:
Innovative studies and offshore construction methods have been used to make this unique multi-opening cable-stayed bridge a reality. It is worth noting, among other things, the adoption and implementation of the shallow foundation solution on a reinforced bottom, the continuous and fully suspended deck along the entire length of the bridge (2,252 m), the large seismic damping system, equipped with special anti-seismic suspension cables, expansion joints that can receive large displacements along the axis of the bridge and transversely.

The head of the design and construction was the French company Vinci in collaboration with the largest Greek construction companies (Aktor, J&P and Athena).

Geophysical Environment of construction of the Project

The environment in which the bridge was built presents a combination of natural adversities that makes this project quite complex, such as the width of the Strait which is about 2,500 meters, the depth of the sea (up to 65 meters) combined with the deep loose alluvial layers the possibility of intense seismic activity, tectonic movements and extremely strong winds.

Subsoil

The relief of the bottom shows steep slopes towards the two shores and a large horizontal level at a depth of about 60 meters below sea level. The investigation of the first 100 meters of the seabed showed the absence of a rocky substrate. According to geological studies, the thickness of the sediments consisting of thick clay layers mixed, in some places, with fine sand and silt exceeds 500 meters.

Earthquakes & tectonic movements

The Corinthian Gulf and more specifically the northern coast of the Peloponnese is characterized by the existence of a large number of active faults, such as Xylokastro, Aigio, Eliki, Psathopyrgos, Patras etc. reflected on the relevant map.

The faults are located the majority of earthquakes recorded in the area as a result of tectonic movements between Central Greece and the Peloponnese that reach a few millimeters per year.

The seismic hazard analysis concluded that an earthquake of near magnitude up to 6.5 on the Richter scale is crucial for the definition of seismic activity in the project area. In the map, the circles and squares correspond to historical and recorded by earthquakes of magnitude greater than 5.5 on the Richter scale.

Winds

Due to the morphology of the surrounding mountains, the Rio-Antirrio Strait is known for its frequent and strong winds. The reference wind speed (hourly average at 10 meters altitude, recovery period 120 years) was estimated at 30 m / sec based on a rich database of wind measurements.

Study loads

Seismic design loads are defined in the form of a response spectrum at sea level. The maximum ground acceleration is 0.48 g and the maximum spectral acceleration is 1.2 g for periods between 0.2 s and 1.0 s. This range is considered to correspond to an earthquake with a recovery period of 2,000 years or to a seismic event with a 5% probability of exceeding for a lifespan of 120 years. In the following figure, the study spectrum of the Bridge is compared with that required by the Greek Earthquake Regulation (EAK 2000).

Given the tectonic movements in the area and the life of the bridge of 120 years, the conventional specifications required the Bridge to be able to receive possible movements of faults up to 2 meters in each direction, horizontally and / or vertically between two successive pedestals, in combination with a vertical slope of 1/500 of the pillars.

The reference wind speed (hourly average at 10 meters altitude, recovery period 120 years) obtained was 32 m / sec. At the level of the deck (57 meters above its surface