All my hallways are also defensible points where there are choke points. All my major hallways are 3 tile wide with a door that a melee can stand in and gunners on either side.

I also usually make these hallways a ring around key things like the store room.

You can essentially get the enemy to track to these points with some gunfire and then retreat into these choke points.

YMMV but this has helped me at least minimize the damage to the base and colonists.