Problem $7$ A consolidation test has been performed on a sample of lodgement till $($subglacial sediment

that are deposited by the ice onto the substrate$)$ from a region that was once covered with a glacier. The

current vertical effective stress at the sample location is $1800$l$($b$)/($f$)$t$^(2)$ and the measured pre$-$consolidation

stress is $32,500$l$($b$)/($f$)$t$^(2).$

$($a$)$ Assuming the glacier was in place long enough for complete consolidation to occur and assuming the

ground surface and groundwater table elevations have remained unchanged, compute the maximum

thickness of the glacier. The specific gravity of glacial ice is about $0\mathrm{.}87.$

$($b$)$ Although glacial ice was present for a very long time, it also extended over very large areas, so the

required drainage distance for the excess pore water was very long. As a result, all of the excess pore

water pressures may not have dissipated. Therefore, our assumption that complete consolidation

occurred may not be accurate. If so$,$ would our computed thickness be too large or too small? Please

explain your reasoning.