Down at the Blainville-sur-Orne port complex…
SADE is building 2 twin XXL lifting stations for the rainwater collection, treatment and discharge project launched by Caen Normandie CCI.
Identical and 50/50
These 2 underground concrete structures, located at either end of the platform, are absolutely identical. They are 7.50m high, 6m long and 3.60m wide, and house four 1,600m3/h pumps operated on a 3+1 basis. Each station is sized to lift half the volumes collected on the site up to a nearby retention and containment basin, meaning the 2 stations treat 100% of the rainwater.
A tried and tested methodology
The concrete structure of each station features 4 prefabricated frames, laid inch-perfectly on top of each other then bolted together. This is precision work involving imposing, heavy components: the lightest weighs 15t and the three others 26t. The frames are waterproofed with seals installed between the layers as they are stacked up. The structure stands on a stabilising 60cm-thick ballast concrete base.
Working safely: the priority!
When working down at significant depth, in a vast trench dug on land with a high water table, a range of special security measures must be put in place. Here, the 8m x 6m, 6m-deep trenches were dug by lowering the water table to 8m and protected by a sheet pile curtain and two HEB belts designed by SIng. Internal scaffolding, assembled up the entire height and around the full perimeter facilitated and secured operators’ work, particularly when setting up the frames. Not only is safety never a waste of time, but when it’s done right, it also optimises our worksites. QED!
SADE specialises in all networks AND all related structures. These XXL lifting stations on tricky terrain prove it.