Hatches can be breached in the same way as soft walls. Operators can breach them using explosive gadgets and certain weapons. Some gadgets exist mainly to blow up a wall or a hatch. Shotgun shells can break hatches, but holes created by other firearms will not let you pass through as they don’t destroy studs.
Like the walls, hatches can be reinforced by the opposing team, requiring specific hard-breaching gadgets to destroy.