Floating, Fast and Always Safe

Flood relief channel for the Armançon river reservoir: mammoth cycles, floating support frames and innovative anchoring on the slope

Data & Facts

  • Project
    • Flood relief channel for water reservoir at Pont-et-Massène, France
  • Builder
    • Navigable waterways authorities
  • Contractor
    • Maïa Sonnier & Maïa Fondations
  • MEVA Systems
    • Support frames STB 450, some with special anchoring
    • Safety system SecuritBasic with wall formwork Mammut 350
    • Wall formwork Mammut 350
  • Engineering
    • MEVA Systèmes de Coffrage SNC, Sarreguemines, France

MEVA ... more than just formwork!

The water reservoir on the Armançon river in central France west of Dijon is used for swimming, sports, fishing, water supply and water level regulation. Built from 1878 to 1882, the old barrage is being completely renovated and equipped with a new high-peformance flood relief channel that is poured with MEVA rental formwork.

Heavy-duty MEVA systems for large scale applications
The new flood relief channel descends like a stair from top to bottom, it is quite steep and equipped with high perimeter walls ensuring that much water can flow off very fast without causing flooding and damage. Where possible, the wall formwork is placed on the horizontal part of a step and the wall section extending along that step poured in one cycle. With wall sections up to 15 m long, the 3.50 m high panels of the heavy-duty ­Mammut 350 system are the ideal choice to pour them fast and efficiently use large-size panel gangs composed of panels height-extended several times and of up to 4 or 5 height-extended units side by side. Such large panel gangs are crane-lifted from cycle to cycle without requiring time-consuming disassembly and re-assembly, thus saving much labour. Much additional time is saved thanks to the system’s 100 kN/ m² fresh concrete capacity that allows for fast pours with an unlimited rate of pouring for the first 4 meters.

The free-standing perimeter wall on the valley side is poured with double-sided wall formwork in combination with the modular SecuritBasic safety system that comes with integrated safety – platforms, ladder access and railings are part of the system and do not require any job-site solutions. The wall sections of the perimeter wall on the hillside are poured with double-sided wall formwork where the distance of the wall to the rock allows for such a solution. All other sections are poured single-sided using STB 450 support frames and Mammut 350 panels.

MEVA ... more than just formwork!
In order to support the heavy loads, the legs of the STB 450 support frames must be attached to anchors cast in the base slab. But what do if there is no base slab? MEVA and Maïa ­Sonnier engineers developed the solution in joint cooperation: The front legs are attached to anchors previously cast in the perimeter wall and the rear legs to a horizontal steel girder. One end of this girder is attached to the adjoing base slab on the samel level, the other end to a vertical steel girder that is firmly attached to the adjoining base slab below.

“This is a unique solution for a problem no one else could solve and one of the reasons why we are using MEVA formwork on this site”, confirms site manager Clément Jouanneau. “I am impressed with the superior quality of the concrete finish, with the performance of the Mammut 350 formwork and the stability of the systems that handle the tough job on this site without problems.”