Assuming that the pool will be constructed below grade, I would offer the following recommendations:
1)Bearing support; in this case the swimming pool would be similar to a slab-on-grade;
2)Earth pressure coefficients for design of the below-grade walls;
3)Groundwater considerations, if applicable;
4)Difficult excavation considerations, if applicable;
5)Temporary slopes during construction and protecting adjacent structures depending on their location relative to the pool construction; and
6)Fill placement criteria.
If the existing site conditions allow, I would perform a couple of soil test borings to analyze the subsurface conditions. Laboratory testing as you see fit.
You may need to consider buoyancy of the pool when it is drained for cleaning.
Also that the weight of material excavated will be roughly twice that of the water filling the void, so you may get an overall unloading condition depending on the weight of the concrete etc in the pool.
Are you talking about a vinyl liner pool or a concrete pool? The two are very different animals. Vinyl liner pools typically have wall sections of sheet metal and are very flexible so there is really not a concern for detailed geotechnical consideration. The exception of course would be the effect on any adjacent structures, slopes, etc.
Concrete pools by their nature need to be constructed to resist cracking, i.e. leaking. Most notably the walls need to be designed to resist the lateral earth pressures an suitably reinforced to prevent cracking. Bouyancy of the pool is also a potential problem, although usually only if the groundwater table is near or above the bottom of the pool. The provision of a drain in the bottom of the pool can effectively deal with this.
Bearing is not really an issue for either type of pool, assuming it is an inground pool. The weight of soil removed is almost twice the weight of water in the pool so the load on the soil is in effect reduced. Of course if the pool is to be constructed in an area of poor fill, organic soils, etc. then some additional support may be need.
The pool manufacturers should be able to provide you the details of their system. Typically the base and sloped portions of the pool are plain concrete (with a fine 'smooth coat' finish), and the side walls are sheet metal panels. The panels typically are about 2.5 feet high and 2 to 8 feet long depending on the arangment and shape of the pool. The wall panels are supported laterally with X braces perpendicular to the walls on about 2 foot centres. The installation practice is to have concrete roughly place (with wheel barrow and shovel) along the base of the wall sections and also a 'blob' of concrete at the base of the X-brace. The backfill behind the walls in usually clearstone. The vinyl liner then attaches to coping at the top of the wall sections and 'fits' into the base of the pool with the weight of water.
I spent a summer in university installing inground pools so have a good first hand knowledge of how they go together. As a geotechnical engineer I have been involved with several swimming pools, however almosts always in the context of slope stability analysis (i.e. pool being constructed on top of a slope). As I noted before there is not usually a need for detailed geotechnical comment on a typical inground vinyl pool. The only exceptions would be if the ground conditions are very poor, adjacent structures that could be effected (undermined) by the excavation, or slope stability concerns.
If poor soil is an issue then supplemental support sould be provided with any number of ground improvement methods. However it would need to be pretty bad soil as the net effect of installing a pool is to reduce the loading on the soil. I suppose if you had a depth of fill greater than the depth of the pool that has been recently placed, or placed without any compaction, then there could be a concern over settlement under the weight of water.
