Is raft foundation plus shear wall equal to box foundation?
No, the function is very different. Foundation refers to the substructure that the building transfers the load to the foundation; In the functional design requirements, the shear wall mainly bears horizontal load; If raft foundation and shear wall are regarded as box foundation, the vertical load is still mainly borne by raft foundation. If the raft foundation and shear wall are regarded as box foundation, the raft foundation should be designed to bear vertical load alone, which may lead to the damage of the raft due to excessive vertical load. So you can't think like this!