Question

3. During a springtime rain event, flow develops through both the sludge and peat layers in the soil profile below. A piezometer with its tip at the base of the peat layer indicates a water rise to 0.6 m above the fill surface (an upward flow condition). What are the new total, elevation, and pressure heads at 0.6m below the top of the sludge layer? Assume head loss occurs through both the sludge and the peat layers. 0.6 m 1 m Fill/Cap Yor= 10.2 kN/m Sludge Yoon= 12 kN/m k = 2 x10 cm/s 0.6 0.6m m 1 m Peat Yor= 11 kN/m k = 9 x10 cm/s 1.5 m

Answer 1

0.6MI datum - equivalent permeability key = Il + 2.57 de lost to = 3.75x100 cm/sec equivalent hydraulic gradient = 16 = 0.64 & 25 2 gradient in sludge. i z 3.75 x 15 6 x 0.64 2 1.2 2x10-6 2 & elevation head = 1+1.5-0.6 = 1.9m pressure head 0.6+ 1.280.6 - 1.32m 2) Total head a 1.32 +1.9= 3.22 m. CILDI.