A soil profile consists of a clay layer underlain by a sand layer as shown in Fig.2-22. If a tube is inserted into the bottom sand layer (Fig.2-22) and the water level rises to lm above the ground surface, determine the vertical ef- fective stress and pore water pressures at A, B, and C. [1m GWL Im at=18.5kN/m Clay 2m Yat=19.0kN/m 1.5m Y17.0kN/m Sand B 2m C- FIGURE 2-22 .... ....