The soil profile at a site consists of a 2.0 m thick sand layer at the top, un- derlain by a 3.0 m thick clay layer. The water table lies at a depth of 1.0 m below the ground level. The bulk and saturated unit weights of the sand are 16kN / m³ and 19kN / m³ respectively. The properties of the clay are wa- ter content = 45.0%, specific gravity of the soil grains dot = 2.7 compression index = 0.65, swell index = 0.08, and overconsolidation ratio = 1.5.

The ground level is raised by placing a 1.5 m high compacted fill with a unit weight of 20kN / m³

What will be the consolidation settlement?