Calculate the cost for excavating a raft foundation with dimension (100 x 100 x 1.25) m in a clay soil using a bulldozer, if you know the following information: Operating factor = 50 Speed during excavating the foundation 4 km/hr. Speed in return =8 km/hr. Distance of soil transfer is 50 m Swelling percentage (Sw) = 22% Fixed time = 0.32 min. Bulldozer blade size = (2.5 x 1) m. Working hours = 8 hr. per day. Cutting cost of rent the bulldozer = 300 x 103 ID/day