This project consists of the construction of a new bridge to replace the existing one in the LM.06 Area of Txomin-Enea, in San Sebastián. The designed bridge has a length of 59.4 m between abutments, divided into two spans of 42 m and 17.4 m, with a single pier located on the left bank, improving hydraulic performance and reducing the cost of foundations. The plan of the new bridge is its most unique feature, as the sidewalk cantilevers open their path in the lower span of 17.4 m until they become independent from the central core of the deck to form side walkways.
The bridge, with a useful section of 18.3 m, presents a 7 m central carriageway, with two 3.2 m lanes, a 4 m cantilevered sidewalk downstream, and a 5.5 m cantilever upstream formed by an exterior sidewalk of 3 m and a bike lane of 2.5 m.
The sidewalk cantilevers are separated from the road by 90 cm wide structural barriers that house the main beams of the structure or edge ribs. These metal beams are located on both sides and have 192 cm of depth, 75 cm below deck surface and 117 cm above deck grade, forming the barriers between the road and sidewalks. Between the main ribs the road is materialized through a mixed slab 21 cm thick. This slab rests on curved metal ribs of variable depth located every 3 m.
The pier, located 17.4 m from abutment 1 so as not to interfere with the river bed, is configured as a sculptural volume in concrete with a metallic core, with ruled surfaces that also improve the hydraulic profile in the event of an avenue. It is made up of two V-shaped arms joined by a metallic upper cross member that acts as a diaphragm between the main nerves of the deck.
