A 6-ft-thick clay layer is located below a thick sand layer and immediately above bedrock. If a surcharge of 250 psf is placed on the ground surface, explain how the total stress, effective stress, and pore water pressure will vary in the top, middle, and bottom of the clay layer as a function of time. At minimum discuss these values at the application of the load, a short time after the load application, and a significantly long time after load application.