The Félix Giorgetti company has built three sections of the Mersch bypass: a cut-and-cover section, the bridge over the Mamer and the Schoenfels interchange.
The A7 motorway has now been diverted so as to bypass the town and avoid residential areas.
The cut-and-cover section, Work O.A.5, comprises a two-way twin-tube structure. The construction was organised so that 10 metres of link section could be completed each week.
The Mamer bridge, Work O.A.6, is a hydraulic, twin-deck slab structure in pre-stressed concrete, with a constant thickness of 1m. Each of its decks was constructed in one single phase, which means 900m3 of concrete was used in just one day.
The Schoenfels interchange forms the crossover between the A7 motorway and the CR102 south-west of Mersch, near Kannerduerf, and comprises several civil engineering structures, of which O.A.7 and O.A.9 were carried out by Félix Giorgetti.
The first, Work O.A.7, is an overpass, a reinforced concrete slab bridge that enables users of the newly modified CR102 road to cross the A7 motorway. The second, Work O.A.9, is a pre-stressed concrete slab viaduct that enables users of the newly modified CR102 to cross the River Mamer.
Since the ground in the Mamer valley is fairly mediocre in terms of its load-bearing capacity, a large number of very deep piles were needed in order to support the structure’s footing system.