The Operation for the rehabilitation of the Rophémel and Néal dams is allocated in 4 lots listed in the RC.

This consultation concerns only lot 1 Civil and Hydromechanical engineering works to rehabilitate the Rophémel and Néal dams, associated structures and hydromechanical equipment.

Rophémel Dam

Resumption of the waterproofing of the upstream cladding by the installation of a Pvc-P geomembrane,

Repair of disorders of reinforced concrete structures,

Rehabilitation or renewal of hydromechanical equipment for flood evacuation, bottom emptying, auxiliary emptying, water intake, etc.

Néal Dam

Resumption of disorders of the masonry downstream facing,

Resumption of the disorders of the quay facing (earthworks of the left bank downstream of the dam).

The contract includes execution studies, earthworks, civil engineering, hydromechanical equipment, control command and electricity.

the work of Lot 1 Civil and Hydromechanical Engineering will be carried out in three phases.

1st phase implementation study and preparatory work

implementation studies,

construction site installations,

Implementation of a construction crane.

2nd phase concerns work that can only be done with drained reservoir:

Rophémel Dam:

O Resumption of the waterproofing of the upstream cladding by the installation of a PVC-P geomembrane,

O Repair of disorders of the reinforced concrete structures of the spillway and platforms on the upstream siding,

o renewal of the manoeuvring equipment of the bottom drain valve,

o Adaptation of the upstream grid of the bottom emptying

o renewal of the cofferdam upstream of the bottom emptying,

o rehabilitation of auxiliary drain valves,

o resumption of the painting of the valves and valves of the spillway,

o resumption of the support of the panels of the screen of the water intake,

o installation of emergency blocks in the hydroelectric power plant immediately downstream of the dam,

o installation of a drome in the tailrace of the hydroelectric power station,

o renewal of the water intake valves of the mine tower located in the reservoir (drinking water plant water intake),

Néal Dam:

O Resumption of disorders of the masonry downstream facing,

o Resumption of disorders of the quay facing (earthworks of the left bank downstream of the dam).

3rd phase concerns the work that will be carried out later after filling the reservoir. :

O Repair of disorders of reinforced concrete structures of downstream facing and ridge gantries,

o Repair of the inter-slab joints of the crown.

Important notes:

Operations on the upstream facing of the Rophémel dam will require the implementation of a construction cofferdam to protect the work area, as well as scaffolding (and possibly nacelles) on the entire upstream facing.

Operations on the ridge and downstream of the Rophémel dam will require the implementation of scaffolding (and possibly the use of other means of access such as nacelles or rope access works).

Operations on the Rophémel dam will require the installation of a construction crane downstream of the dam on the right bank whose spire must be at least equal to 75 m. This crane will be used for other operations outside the scope of this contract.