Pergamon Bridge

39.12157527.182674Koordinaten: 39 ° 7 ' 17.7 "N, 27 ° 10' 57.6 " E

F1

Selinus ( Bergama Çayı )

The Bridge of Pergamon is a Roman River Complex in the ancient city of Pergamon (now Bergama ) in Turkey. The double tube at the forecourt of the Red Hall, with a length of 183 and 196 m far the largest river redevelopment antiquity.

Classification as flow overbuilding

The consistently above ground applied to bridge of Pergamon is often referred to misleadingly as a tunnel due to their unusual width in the literature. It possesses a tunnel similar hydraulic and hydrological characteristics, but in their design came entirely different construction techniques used, since considering its position on day neither the determination of the direction of propulsion nor the risk of water ingress or Deckeneinstürzen played a role. It makes sense, therefore, it is loud Grewe, to speak of a river overbuilding, the construction of a particularly wide solid bridge corresponds, in which the load of the barrel vault is captured by the abutment and the wall between the two tubes perceives the static function of a center pillar.

Urban planning, such substructures offer especially when in the midst of the city - as it were in a prime location - a large open space for public or other structures to be obtained. This was also the case in Pergamon, where the time of Hadrian ( r. 117-138 AD), a significant part of the city's river Selinus (now Bergama Çayı ) was bridged to make room for the forecourt of the temple of the Egyptian gods (also to create a temple of Serapis or Red Hall known) (another example in Asia Minor is the bridge of Nysa ).

Construction

The river overbuilding of Pergamon consists of a rectilinear double tube with two parallel barrel vaults, between which a continuous partition is running. The difference in length between the western (183 m) and eastern tube ( 196 m) results from the fact that the - the mountain side lying at an altitude - tunnel openings forming displaced towards the valley 13 m. As a result of after-market threshold of 2 m off the western tunnel is now partly silted. The dimensions of the two semi-circular arches are virtually identical: The span will be 9 m, height from the stitch fighters point to the bow apex 4.5 m and the clear height of 7.5 m. The walled up of unprocessed stones in the solid mortar Association vault located on both sides on a foundation of stone blocks.

Above and below the river overbuilding cross two bridges ancient well preserved the Selinus, the tobacco Köprüsü and Üç Kemer Köprüsü ( "Three Arch Bridge ").

Flow capacity

The limit capacity of the river overbuilding during floods has been the subject of hydraulic and hydrological investigations. In a gradient of 0.6 %, a maximum flow capacity of 360 m³ / s per tunnel was determined before the Selinus dams up, the building is under internal pressure and cause damage. If one this value based on that of Selinus is 13.4 km long, has an average gradient of 2.2% and includes a catchment area of 101 km ², emerge depending on the method following average recurrence intervals:

This would make statistically every 700 years old - the value that designates Grewe as the " arithmetic mean " - to expect a flood that exceeds the capacity of the bridge of Pergamon.