A multistory building with a plan area of 200 ft by 100 ft will impose an estimated total loading of 20,000 kips onto the supporting earth. If the floating foundation concept is to be utilized for...

A multistory building with a plan area of 200 ft by 100 ft will impose an estimated total loading of 20,000 kips onto the supporting earth. If the floating foundation concept is to be utilized for this structure and the average unit weight of soil underlying the site is 120 pcf, what volume of soil excavation (and subsurface structure) is required?