can other items be put in a concrete trench in building with electrical cables in conduit ,what is the separation. this will be a concrete trench with removable cover in building.
Is just a hollow space in the building just like a wall stud cavity, you can put raceways, cables, communications cables, plumbing, etc. in there. You can't put individual conductors that are intended to be installed within a raceway in there, just like you can't put those in a stud cavity in a wall without installing them in a raceway.