A rectangular excavation is $80$ m long and $40$ m wide. The groundwater level is $1$ mbelow the surface: an impermeable stratum lies at a depth of $13\mathrm{.}5$ m$.$ The average permeability of the aquifer is $5$ x $10-4$ m$/$s$.$ The excavation is to be $5\mathrm{.}5$ m deep. The lowered groundwater is to be at least $0\mathrm{.}5$ m below the base of the excavation.

$*$ Find Qtot for an equivalent circular excavation. You may start assuming ho $=4$ m$.$

$*$ Estimate the number of wells required for r $=0\mathrm{.}10$ m$.$ Check the value assumed$$for ho and improve it if required, revising Qtot$-$

$*$ Locate the wells around the excavation, and check the lowered water level at the most critical point using Forchheimer's equation.