This is an example on how some concrete pools were constructed. A concrete floor was poured in place. Then they used the outside perimeter of the floor as a footing to build the walls out of concrete blocks. Not the best method to contain water and really limited the shape of these types of pools.
Once again, the entire structure, suction, returns, coping and filtration lines needed to be replaced. Watertown changed the angle of each corner from 90 degrees to a 6″ cut corner. This allowed the liner to stay in the track much better and helped with the water circulation. We formed and poured a pea stone cap around the perimeter of the pool, then a new concrete pool deck complete.