Which empty conduits are under a precast concrete garage with strip foundation

The cables have already been routed outside through the multi-duct. It is only a matter of getting them into the garage now.

Or does anyone have a better idea?

The option with the slotted drainage pipe is certainly the easiest to lay.

With KG pipes, pulling cables later feels easier, right? The problem is only the joints. Possibly, I could also butt the KG pipes for the spaces between the foundations and then attach them to the foundations using metal brackets, e.g. on the "free" pipe with screw/nut and on the foundation with screw/anchor?

KG pipe is great for pulling cables through. Connections must of course be 100% tight, since they are later in the concrete? If concrete gets inside, that is very, very bad. I would also mechanically fasten it and, for safety, seal it thoroughly on the outside again with PU foam.

Or does anyone have a better idea?

Franconian Kabuflex R, that's exactly made for something like this and comes in numerous diameters.

KG pipe is great for pulling cables through. Connections must of course be 100% tight, since they will be in concrete later? If concrete runs in, that is very, very bad. I would also mechanically secure it and, for safety, properly seal around it on the outside with PU foam.

Hey, thanks for the info. No, only the sections in the strip foundation are in the concrete and are already installed. The garage "floats" above that, and the remaining pipes lie on the ground, i.e., between the soil and the underside of the garage floor. At most, sand, soil, and animals can get in there. Since I'm installing underground cables anyway, I assumed the pipes are only supposed to make it easier to lay cables later. I don't think waterproofing is necessary then. The tip regarding mechanical securing is good though. Maybe I'll drive a few metal rods into the ground and fix the pipes with wire and soil.

Fränkische Kabuflex R, that is exactly made for something like that and is available in numerous diameters.

I have also found those, but I would have to order them separately and they are only available in 50m coils at corresponding costs. I thought, since I basically only need a conduit for the gap between the ground and the underside of the garage, I can use any pipe. It also doesn't have to be waterproof, as underground cables are planned. With DN110, one could also add a garden hose or something later on. That’s why the idea of the drainage hose came up. I would bury it about 10cm deep (no more is possible). Unlike KG pipes, water does not accumulate there.