Trèbes: after the repairs on the canal bridge, it’s time to clean up the Orbiel

Following the floods of October 14 and 15, 2018 between Carcassonne and Trèbes, the Canal du Midi suffered major damage: overflow, breakage of dikes in several places, washouts on the banks, falling trees.

Faced with an unprecedented situation, the teams of VNF (Voies navigables de France) were mobilized to carry out a precise inventory of the state of the premises and plan major cleaning and securing operations. The Canal du Midi was filled with silt, ice jams, sediments and other materials, the Aude having passed over this canal at the height of Villedubert, the Orbiel, at the level of Trèbes.

Swelled by the heavy rains, the river exceeded 6 m submerging the canal bridge, carrying parapet and guardrail and leaving visible fibers and other materials. The right bank has been reinforced, on the downstream side of the bridge, to create a passage for large machinery carrying out the work. The first row of stones on which the parapets and railings rested were washed away by the waves, with them, leaving only holes. 40 m of alignment and 25 m on each side were replaced, resulting in major masonry work to reconstruct this row of stones.

On site in anticipation of the work

One of the damaged bridge piers was recovered and, to date, does not present any danger. The two bridge abutments (extreme supports serving as ground support on which the deck rests) have been consolidated.

A feasibility study was carried out to put a guardrail to safety standards validated by the architect of the Buildings of France. In the meantime and at the request of the municipality, VNF has temporarily affixed a fence ensuring the safety of users.

At the beginning of October, Jérôme Comméléra, head of the Territorial Center and Arnaud Seguy, works and primary maintenance project manager for VNF came to the site in anticipation of the works, with the Smarr, to clean and devegetate the bed of the Orbiel to the right of the bridge. -channel. To ensure the best flow of water.

Jérôme Commelera clarified: “Immediately after the crisis, several teams were present in the affected sector for cleaning operations, securing the structures and paths, guaranteeing monitoring of the structure, involving internal and external resources from the outset. In the early hours of the decline, a very precise inventory of the disorders was carried out, coordinated by the SI3E of the DTSO. The list of actions to be carried out was established over several timeframes: securing in the short term, work necessary for the return to navigation, and those which could The proper coordination of all the stakeholders required particular care: interventions by the VNF DTSO teams on the one hand, by several companies on the other, and coordination of the whole to optimize the calendar.

The VNF DTSO teams intervened in areas inaccessible from the road, in river interventions, to clear and dredge the jams, and to restore the hydraulic and electrical systems of the locks.

All the services of the Territorial Department have been mobilized, both at the administrative (legal, public procurement, communication, etc.) and technical levels. 4.5 million euros were needed for the rehabilitation of some 20 km which were particularly affected by this flood”.

Structural expertise. Recovery and reinforcement of the bridge abutments, downstream side. Resumption of the upper layer of stones, base of the degraded and displaced railing. Resumption of calades in freestone and pebbles. Reinforcement of a bridge pier. Removal of jams and materials to the right of the bridge, in the Canal and in the entire reach concerned by the passage of the Orbiel. A feasibility study was carried out on the installation of a new security guardrail.