Just tell them straightly that you are there to work not to have some ted talks, and by knowing that they're going to avoid you when they've got something to vent to you as you've already vented to them about what you dislike.
Some people are very bad with social clues so it is needed sometimes to directly tell them what you need and don’t need. You are all trying to work so I am sure they will appreciate it if you all had a productive and professional relationship with one another.
Just choose your words wisely and I am sure they will understand and step back or away from you.