That is not going to blow away in a hurry!
Good set of piccies Mick.
I have not used any concrete anywhere but have had moments where I wished that I had as the clay ground under my layout swells and contracts. Even with posts driven deep into the ground the movement affects the lie of the track.
I do tell a little lie though....the quarry section is actually on a concrete base that I had already 'landscaped' with slate rocks, small stones and scree. The track is just 'laid' on top of slate scree and then ballasted with more scree with only track ties keeping it all together...funnily it has been the best behaved part of the layout!
Before the layout was even a gleam in my eye the, what was to be, quarry section was 'landscaped' on top of a concreted slab area between the wall
Track was just laid on top of the scree and some buildings added
More buildings and detailing added
Because of the concrete everything is very stable...unlike the rest of the layout. Your layout will be around for a long time Mick....maybe it will be an archaelogical site hundreds of years in the future
