I could not understand the 1.4 ton/m2 live load. What will the building be used for? Does the same purpose apply to the roof? Does it also apply to the top of the stair tower? A large part of your problem stems from this load analysis. I can't comment because I don't know. If you will continue to use the same loads, I tried a basic system as in the attached picture. I used continuous foundations and a raft system connected by continuous wires. The raft thickness was 60 cm and the foundation thickness was 100 cm. It can fall more if it is worked on. No problem appears. It will be more economical if you reduce the diameters of raft flooring and continuous foundation beam reinforcements. I've always tried a solution as a foundation as well. It doesn't save 1-2 foundation beams with 200/100 size foundation. Economic methods can also be found to find a solution if worked on. But I'm still stuck with the load. Will the load in question affect the building at any time? Wouldn't you consider applying the live load reduction agent? Good work.