Thrust block in Air cooler

What is thrust block.? Where it is used in Air cooler layout.

A thrust block is like directional anchor that is installed in the ground. When you have buried piping that has a high or low temperature rating, this temperature range causes the piping to expand ...or contract (even though it it's buried). Where this piping enters the ground, in loose or sandy soil, the piping can push the soil away and move, this can put a stress load back on equipment nozzles there the piping started (or ended) from ...a "bad" situation! SO to direct the movement away from this entry/exit point, you put in a "thrust block" in the earth against the piping to direct the movement away from this point. Actually this is nothing fancy, all it is a large concrete block (4 ft cube ...or larger/smaller depending on the size and temp of the piping) that gives a solid unmovable point that the piping can push off from. This thrust block is usually cast in place in the ground and around about half the profile of the piping at this point so the piping is indexed to the thrust block, this won’t let the piping try to crawl around this block if the movement tried changing directions.
As far as any “standard piping” configurations to pipe up an “air cooler” …I’m not familiar with any equipment under that name, but it shouldn't be much different from the basic description I laid out in my explanation above. FYI …Size and use of a thrust block is NOT something a piping designer generates! This is normally accomplished by a combination of efforts by a stress engineer and a soils engineer work together and give the requirements to the designer. Good Luck!

I was told that when there are more than 8 units of air cooler, thrust blocks are used to transfer lateral movement of individual units to compensate header movement.These blocks are placed in between units. But I haven't seen such an arrangement of thrust blocks.

8 Units!!? ...Sounds like the header size is fairly large, if so I could see it being buried. I don't believe you'd need 8 individual thrust blocks; maybe 2 (if the units are spaced close enough) ...one at end of the header and maybe one near the middle, still they'd would tend to be large, especially if the soil is loose and sandy. The trick is to come up with a configuration at the inlet and discharge piping of each unit, before it enters/exits the ground, which allows for some degree of movement.
Sounds like an interesting project ...Good Luck!