Round conduits? Your rectangular 'hole' will have to be formed up and circular sleeves in place where the conduits go. You have to fill the form with concrete making sure the perimeter is water tight. After the concrete sets, you remove the formwork and fit the conduits through it. You then have to waterproof around the conduits.
You can cast the wall solid, and drill through for your conduits, remembering to place the reinforcing so it's not cut when you drill.
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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates
-Dik