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1.Easy
A 7 m thick normally consolidated clay layer (γsat = 19.5 kN/m³, Cc = 0.15, e₀ = 1.05) lies below 3 m of sand (γ = 17 kN/m³). The water table is at the top of the clay; use γw = 9.81 kN/m³. A wide fill raises the vertical stress throughout the clay by 100 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.
sand: Hs = 3 m, γ = 17 kN/m³clay: H = 7 m, γsat = 19.5 kN/m³γw = 9.81 kN/m³Cc = 0.15e0 = 1.05Δσ = 100 kPa
S = mm
2.Easy
A 3 m thick normally consolidated clay layer (γsat = 19.5 kN/m³, Cc = 0.35, e₀ = 1.25) lies below 4.5 m of sand (γ = 18 kN/m³). The water table is at the top of the clay; use γw = 9.81 kN/m³. A wide fill raises the vertical stress throughout the clay by 105 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.
sand: Hs = 4.5 m, γ = 18 kN/m³clay: H = 3 m, γsat = 19.5 kN/m³γw = 9.81 kN/m³Cc = 0.35e0 = 1.25Δσ = 105 kPa
S = mm
3.Medium
A 3.5 m thick overconsolidated clay layer has Cc = 0.3, Cr = 0.06 and e₀ = 0.8. At its mid-depth the effective vertical stress is 50 kPa and the overconsolidation ratio is OCR = 1.5. A new building adds 180 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A 6 m thick overconsolidated clay layer has Cc = 0.3, Cr = 0.06 and e₀ = 0.8. At its mid-depth the effective vertical stress is 100 kPa and the preconsolidation pressure is 140 kPa. A new building adds 35 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A clay layer 4.5 m thick has a coefficient of consolidation cv = 2 m²/year. It lies on impervious rock, with sand above it, so water drains out only at the top. For 80% average consolidation the time factor is Tv = 0.567. How many years t does the layer take to reach 80% consolidation?
A clay layer 3.5 m thick has a coefficient of consolidation cv = 2 m²/year. It lies on impervious rock, with sand above it, so water drains out only at the top. For 80% average consolidation the time factor is Tv = 0.567. How many years t does the layer take to reach 80% consolidation?