CE $440-$ Intro to Geotechnical Engineering

Design Project $1$: Consolidation

A tank is constructed to contain unrefined crude oil at a site that has $25$ feet of NC clay above a claystone bedrock. The GWT is located at near the surface. The tank is made of a structural steel with a diameter of $50$ feet, a height of $30$ feet, and the thickness of the walls, top, and bottom is $1$ inch $.$ It rests on a solid concrete foundation that is $50$ feet in diameter and two feet thick. Consolidation tests were performed on samples taken from the center of the clay layer and found the compression index to be $0\mathrm{.}72,$ the recompression index to be $0\mathrm{.}08,$ the moisture content of $48\%,$ and the coefficient of consolidation is $0\mathrm{.}293f\frac{t^2}{?}$ day.

Calculate the settlement $($in ft $)$ at the center of the tank using $5$ equal layers if the petroleum is filled to capacity $(29$ feet high$)$ in the tank.

Calculate the differential settlement $($in ft $)$ between the center and the edge of the tank in the same scenario as Part a$.$

Calculate the time $($in months$)$ for $50\%$ consolidation at the center in the same scenario as Part a$.$

Initially the tank is filled to half capacity and kept constant for two years.

a$.$ Calculate the settlement $($in ft $)$ at the center of the tank after the two years.

b$.$ The tank is then drained. Calculate the rebound $($in ft $)$ at the center after the tank is emptied $($hint: The same equations apply, but the initial void ratio has now changed and the change in stress is reducing$)$