Several questions -
(1) you have indicated that the soils testing was done to depths of 150 ft.? Wow, this is pretty deep unless there are other circumstances that we are unaware. Is your clubhouse on 'level' land or, like one job I was involved with, does the clubhouse border on a steep slope?
(2) Is there any explanation as to what is "blown, sandy soil"? Are you in Iowa or other locations with known deposits of loess? Loess has a propensity of collapsing upon watering. If so, perhaps, over the years (and I a presuming tha the clubhouse isn't 'new'), the bits of ground/turf watering about the clubhouse there could be some collapse of the loess structure.
(3) How old is your clubhouse - when did the cracking first appear? If it is relatively old, say 15 years as a point of discussion, and the cracking did not appear until recently, then there may be something other than simple "soil incapable of supporting loads without distress" syndrome. You would want to look into environmental changes or physical/operating changes that has taken/is taking place that might be a causative factor.
(4) Is there any standard penetration test "N" values given for the soil stratum in your soils testing report/log? This would lead to descriptions such as loose, compact (or medium dense) or dense being used on the logs - if, in fact, they were. Assuming that you don't have (2), for settlements to occur "N" values would have to be quite low - in the order of 4 or less and, at that, I would be surprised if these settlements wouldn't have occurred soon after construction - if they did, then see (3).
Once these factors have been noted - a rational approach to the best course of action could be developed. If, as you have, indicated, the cracking is substantial rendering the clubhouse non-functional, then replacement may be the best policy. But, you want to know the points above that will lead to the most suitable choice of foundations or ground treatment to use.
Basically, if new loadings are relatively high, use of stiff mat (raft) or grillage style foundations can be considered. Any settlements would be more or less uniform - differential movements minimized.
Deep foundations (shallow piers, driven pipe/timber piles, auger cast-in-place piles, stone columns) could be considered but as mobilization of equipment will be of large initial cost, be sure that this is more appropriate than using raft/mat/grillage or even spread foundations.
Else, you could treat the ground such as via dynamic compaction - but this sets up high stresses and might affect nearby structures (yours or those of others).
The best choice of foundation type would be based on loadings of new structure, the actual support characteristics of the site 'blown, sandy soil' - which, by the way is a very poor engineering description that leads me to ponder about the drilling company (hopefully not an geotechnical drilling company), external constraints.
I would approach a local geotechnical firm - of good reputation - to help you down the path. Doesn't your club have any members that are geotechnical engineers?
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