Bridges “Village des Tunisiens”, ALGERS

The road bridges are a group of four and overpass the railways tracks located in the Village des Tunisien area in Algers and the Oued El Harrach in the nearby position.

Each overpass is constituted of two parallel bridges with a 15.50m width, a 90.95m free span and a 0.90m central camber.

The structural scheme is a free supported bow string with a couple of arches inclined 21° towards the longitudinal center line with a 14.19m maximum elevation and composed of welded box sections 1500 by 800 mm.

Four transverse box section 800 by 400mm connect the twin arches .

The deck is composed of transverse welded I beams at 4.85m center lines with a depth variable from 850 to 1000mm which support precast rc slabs and the cast in situ concrete topping for the total depth of 0.30m.

The relevant bearing actions are transferred to the arches by means of suspension stays located along the longitudinal string beam.

The 460 grade bar stays feature variable inclinations and converge to a centre located 110m over the axe of the string beam; standard end pin and fork connections are used.

The stability during the construction is assured by horizontal bracing elements located below the concrete slab.

Seismic isolators are installed at the bridge four bearing points over the abutments and also resist the wind and the vehicle braking actions allowing also quite free temperature displacements.