Nysa Bridge

37.90340528.145514Koordinaten: 37 ° 54 ' 12.3 "N, 28 ° 8' 43.9 " E

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Cakircak

The Bridge of Nysa is a Roman River Complex on the Cakircak -Bach in Nysa ( Caria ), today's Sultanhisar in Turkey. The 100 m long, tunnel-like superstructure of the late imperial period was in ancient times by the Pergamon in the second largest of its kind

Classification

The Nysa Bridge spans the transverse through the ancient city area Cakircak - stream over a total length of about 100 m, which gives it the character of a tube or a tunnel in the eye of the casual observer. Despite appearances but it is in the erected structure continuously over days to a river overbuilding, that is, an extra wide solid bridge that bridge and tunnel elements unites in itself: while the hydraulic and hydrological characteristics are a tunnel comparable, as on two abutments resting arc structurally a bridge whose surface disposal typical for tunnel engineering challenges such as determining the direction of propulsion underground or precaution against the ceiling or water leaks could be dispensed with entirely. Flussüberbauten to cover longer distances, a watercourse served in the ancient world, especially to increase the urban area. In the case of Nysas Bauzweck was to create a spacious forecourt for the nearby creek at the theater.

Dating

Already living in Greek geographer Strabo Nysa ( 63 BC -21 AD) described a secret, water-conducting transition in the city, although it is unclear whether this still exists today, the river overbuilding was meant. Based on an attached in the north wall of the tube near the bend inscription that points to one of the builder ( " work of Praülos up to here " ), the bridge of Nysa is dated in the late imperial period.

Construction

The Nysa - bridge consists of a single, 5.7 -m-wide tube that expands to 7 m on the mountain side mouth hole. The rise of the circular arc which attaches about 3 m above the foundation level, is 2.95 m, so that the total height is 5.9 m. The vault consists of unprocessed stones in mortar Association and rests on a base made of different sizes slammed stone blocks with a size of 0.3-0.9 × 1.0-1.4 m.

The originally continuous flow overbuilding is now collapsed in two places: In the upper section the closed vaulting has received 75 m long, 25 m after the tunnel makes a sharp bend. Following the overlapped portion is followed by a 10 m wide Versturzbereich, after the overbuilding continues as a single sheet, which is often mistakenly referred to because of its isolated location as a separate bridge. The downslope end of the tube is also collapsed, so that the total width of the bridge was probably 100 m - a bridge width, which was only surpassed in ancient times from the double structure at Pergamon. For comparison, the width of normal, not acting as a substructions Roman bridges usually did not exceed 10 meters.

In its further course through the urban area of Nysa the Cakircak crossed the stadium, where so water competitions could be held. Two bridges above and below the stadium has remained in ruins.

Flow capacity

The limiting capacity of the river overbuilding during floods has been the subject of hydraulic and hydrological investigations. In a gradient of 3.3%, a maximum flow capacity of 290 m³ / s of the tunnel was determined before the Cakircak Brook dams up, the building is under internal pressure and cause damage. If one this value that underlies the Cakircak is 6 km long, has an average gradient of 19% and includes a catchment area of 4 km ², arise depending on the method following average recurrence intervals:

This would make all statistically 13,500 years - the value that designates Grewe as the " arithmetic mean " - to expect a flood that exceeds the capacity of the bridge of Nysa.