For a green house I'm considering laminate post and beam construction, as described here:

Laminating small timber frame



For piers I thought I might set  16-Gauge Structural Metal Track into cement.




They are rather strong, and two lengths set 4.5" apart, the openings facing one another could make for a cheap socket to set my laminated beams into.
Through bolted in place, with a spacer to keep the ends off of the concrete, I could build up from there.

I originally thought to use bed rails in a similar fashion as they are even stronger, but they are harder to cut or drill, and not as perfectly suited to 2 x 4 construction.

Setting the bottom of the posts in gravel/rocks, and or using cedar for the bottom of the post are possibilities, but right now I'm leaning towards a concrete/rubble pier with diagonally driven rebar or bed rails to resist frost heave.
My site is really hard to dig in, filled with rubble from the house burned down, so avoiding belled piers is good.
Getting enough stone is a balance between time, money and effort.
Buying a bag of cement is cheap, easy and I can add on hand rubble to the mix for even greater economy.

I wouldn't bother with any piers at all except I REALLY don't want my structure to blow down.
My fence on that site already did, it hurt my pride
Buildings have an advantage against wind, but I also plan on keeping more important contents inside.
Plus, I like to get smarter from my mistakes...

Anyhow, what do ya'll think?

(Edited for working links)

The link did not work for me, but I THINK I know what you are referring too.

Myself I have built round wood structures before (once) and it worked, and was strong enough to be dragged about 1/4 mile up the road for a lambing barn, but it was really hard to build not having a "flat" surface to index off from. With my own sawmill, honestly, it is just a lot easier to make framing lumber, and use truss construction saving a lot of logs.

So I like the idea of timber framing with framing lumber.

I am wondering about the "rebar on an angle" though, only because it would seem frost would work on it even more. With posts, gnerally they are placed into a hole, or are pounded beloe the frost line for permant structures like buildinsg. The frost then "slides" up and down the sides of the post harmlessly. here in Maine we watch the shows where they pour a bag of concrete into the hole and scoff because it just does not work here. The frost would grip onto that jagged edge concrete and lift the post right out of the ground. Frost is unforgiving that way, when there is water and it freezes, it has to go somewhere, up by 11% no matter if it is a 50 pounds on top of it, or a 3 story building.

I am assuming fiscally a small excvator rental is out of the question? It sounds like you have the ideal place for a rubble filled foundation. I really like that form of construction, only because if water is drained to daylight, there is no frost, and if there is no frost, there is no heaving. I always like using what I got, and it sounds like you have plenty of rubble. Really the only trouble is digging the trenches, but a small excavator would make quick work of that. It might be a good $250 spent?

Thanks for your reply.
The rebar idea came from looking at the Diamond Peir product, which is a precast concrete block.
4 steel pipes are driven diagonally through holes in the block, to well below frost depth.
A tape is inserted into the pipe to show the inspector,and then it is capped against moisture.

Being both cheap and poor, I thought digging a hole and driving the pipes(rebar) before pouring might work as well.
I believe the pipes in the original product are supposed to act like the "bell" at the bottom of a conventional poured concrete peir , anchoring the peir against frost heave by being set into frost free earth.

Given the twice over unknown nature of the idea, I'm leaning to towards hiring an guy for a days work augering out some holes.
I could use a lot of holes, even randomly placed ones.
I figure a deep hole filled with logs, sticks and wood chips would be an excellent infiltration basin of sorts.
Even with loads of wood chips, the land both pools and loses water.

Something I learned here on the forum might be my ticket to a nice peir foundation.
Post held in place by large angular rocks(will rubble do 😁?),  are kept dry and secure.
I am currently doing this with buckets and 2x4's .
The bucket drain through openings in their bottoms and sides.
An eight foot 2x4 is secured in the middle of the bucket by fist sized stones.
The 2x4's are untreated, but holding up well.
They get wet, but they don't sit in water, so they don't wick it up.
Buckets are fine for a reversible experiment, but I need a foundation that I can count on.
I'm wondering, what keeps soil out of a rubble foundation?