Soil profile shown below along with the standard penetration numbers (N60) in the clay layer. Using Mayne and Kemper equation, determine the pre-consolidation pressure, o of clay at the mid-depth of the clay layer (point A). 1.5m 1.5m 1.5 m Groundwater table 1.8 1.5m # 1.5m 10 Dry sand y 16.5 kN/m Sand You - 19 kN/m Clay Yu-16.8 kN/m Sand