There are two reasons for insufficient raft foundation reinforcement:
The first is that the area of reinforcement required for the raft foundation is not sufficient with the selected raft foundation reinforcement diameters and intervals. In the program, the raft foundation reinforcements are determined according to the reinforcement diameters you choose and the reinforcement intervals determined by the parameters. Choosing a larger reinforcement diameter may be a solution.
Second, although the raft foundation main reinforcements are sufficient, the diameter and spacing of the additional reinforcement do not provide the required reinforcement area. The solution to this problem can only be achieved by intervening in additional reinforcement diameters and spacings.