The foundation of a skyscraper needs to go deep into the earth to be able to support the weight of a skyscraper pressing down on the earths surface.
When building skyscrapers they drive pile down into the earth at depths of 173 feet to be able to sustain the weight of the skyscraper.
The piles for a skyscraper are driven 173 feet down beneath the surface into the clay until they reach a layer of stiff sand.