A three-storey building is to be constructed on a sand beach. Ground water rises to a maximumof 3 m below ground level. The beach sand has the following properties: γd = 17.5 kN/m3, φ = 32° (Nc = 40,Nq = 25, Nγ = 30). The maximum column load will be 700 kN. Determine the sizes of footing for depths of 1m and 2 m using a factor of safety of 3. Settlement are not to be considered. Evaluate the two alternativesfrom practical consideration (difficulties of construction and cost).