Question 2 a) Draw an annotated sketch showing the main features of the oedometer apparatus. What is this apparatus used for? b) Explain the term "isochrone of excess pore pressure". [6 marks] [4 marks] c) The soil profile of a site consists of a 10m clay layer underlain by impermeable bedrock. The groundwater level is at the soil surface (i.e. top of clay). A 2m thick layer of granular fill (assume that y=20kN/m) is placed on top of the clay. Plot the initial and final isochrones of excess pore pressure in the clay and, in the same plot, sketch qualitatively two intermediate isochrones. [10 marks]