in designing foundations, first you need to determine its use and the type of loadings it will resist. It should be in a way that possess enough safety against loads like earthquake or overloading and must be able to resist external environmental attacks (like chemicals and substances that are present in ground water). The dimensions of the designed foundation would also be designed along with it's reinforcements. Step-by-step explanation What is a deep foundation? It is a type of foundation used to transfer and distribute loads vertically from the structure to the depths of the earth. This type of foundation is used when the required/designed loads cannot be supported using shallow foundations. The following are type of deep foundations: 1. Pile foundation - a tapered column that is capable of transferring structural loads and distribute it vertically to the underlying layers. This is used for buildings and bridges to carry its vertical loads. It is also used to resist lateral loads for retaining walls and bridges. 2. Basement Foundation - this is a type of deep foundation that is used for dwelling. It is a hollow substructure that is designed for use below ground level or for current storage space