Sliding barn door threshold/cill

[50flathead]

Been a lurker here for a while and finally have something to post. Just purchased a property with a couple of small Morton buildings. The smaller building has three 10' sliding doors. The larger building has an 18' slider and three 9' sliders. The 18 footer has a stabilizer in the ground in the middle of the 18' door. That in ground stabilizer is a pain to negotiate around plus it sticks up due to the floor being left bare.
A friend of mine has a similar but larger building with sliding doors that are built with wooden thresholds. Anybody know how these are constructed? How can these overcome frost heaving?

 

[cyamaha2007]

Our farm equipment sheds have wooden thresholds. every 4ft they have a railroad tie standing vertical 4ft in the ground. Works just fine.

 

[50flathead]

I'm going to talk to a guy I know that does railroad crossing work. Sounds like a good way to go.