The soil profile at a site consists of 1.5 m of sand underlain by a 6 m thick clay layer. The water table coincides with the top of the sand layer. The saturated unit weight (Ysat) of the sand and clay is 20.0 kN/m and 20.6 kN/m, respectively. The properties of the clay at the centre of the layer include: water content (w) = 22.5%, specific gravity of the solid grains (Gs) = 2.70, compression index (C) = 0.23 and swell index (Cs) = 0.05, and pre-consolidation pressure of 8 kPa. Prior to construction of a large warehouse, the ground was pre-loaded by placing a 3.5 m lift of well-drained, compacted fill with a unit weight of 20.0 kN/m. (Note: Use Ywater = 10 kN/m3 and only one layer for the settlement calculations for convenience. Ensure to track void ratio and clay layer thickness after each loading/unloading step.) a) What is the consolidation settlement and resulting thickness of the clay layer due to the placement of the compacted fill? (4 marks) b) When the consolidation settlement due to the addition of the compacted fill was complete, 2.5 m of the compacted fill was stripped away and removed from the soil profile in preparation for the construction of the warehouse. How much will the clay layer swell and what is the new thickness of the clay layer? (3 marks)