In Picus Communications, when you have to wait for the Funicular to come up, there will be enemies that will arrive to fight you. Before you hit the elevator button, block both entrances into the room with heavy objects. This is only possible if you have the Move/Lift Heavy Objects augment.

There are two vending machines outside the room, two crates (one short, one big) next to the security computer, and the turret in the center that can be used to block the lower doorway and the side corridor.

If you block the doorways correctly, the guards will stay in another room outside the whole time you're waiting for the Funicular. It would be wise to save before you hit the elevator button in case the barricades don't work.