Manager - Project Manager - Civil Engineer
Reconstruction Of The Pissot Corniche Structures
The Pissot corniche structures are located on the RC 705a road linking Château-d’Oex and Bulle. These structures were built in a particularly steep area of the Pissot Gorge in the 1940s and are located close to each other in the town of Château-d’Oex.
These similar structures were built of prefabricated concrete girders with a cast-in-place reinforced concrete deck. The girders rest on massive concrete buttresses that are supported by rock. Natural stone masonry retaining walls hold back the ground between the buttresses.
Following a survey of the condition of the structures and an assessment of their bearing capacity, reconstruction was required because the existing structures no longer met current traffic requirements. The new structures are slightly wider to ensure the useful width of the roadway and create a curb on the edge.
The new reinforced concrete deck rests on the existing buttresses. The concrete on the surface of the buttresses was hydroblasted to remove any chloride-saturated concrete. Then minimal reinforcement was placed over the surface of the buttresses, and self-consolidating cast-in-place concrete was used to create a thick layer around the buttresses.
The new reinforced concrete deck consists of a uniform slab and a curb that were cast in place over scaffoldings resting on rock. The stone retaining walls were reinforced with shotcrete and passive anchors. Passive anchors at the top and bottom of the buttresses enhance the corniches’ stability. The rocky foundation of each buttress is protected from deterioration by a soil-nail wall with reinforced shotcrete. Finally, a layer of aggregate was placed on the deck before asphalt was applied to create a homogeneous pavement superstructure across the entire width of the road.Share