A 10-m-thick, water-bearing sand layer (permeable), called an aquifer, is sandwiched between a 6-m clay layer (impermeable) at the top and bedrock (impermeable) at the bottom. The groundwater level is at the ground surface. An open pipe is placed at the top of the sand layer. Water in the pipe rises to a height of 5 m above the groundwater level. The water contents of the clay and sand are 52% and 8%, respectively.
(a) Does an artesian condition exist? Why?
(b) Plot the distribution of vertical total and effective stresses, and pore water pressure with depth up to a depth of 10 m.
(c) If Ko of the clay is 0.5 and Ko of the sand is 0.45, plot the distribution of lateral total and effective stresses.
(d) An invert (surface of the bottom arc) level of 4 m from the ground surface is proposed for a water pipe 2 m in diameter. Draw the soil profile and locate the water pipe. Explain any issue (justify with calculations) with locating the water pipe at the proposed invert level.