A 3 m thick layer of normally consolidated clay (Cc = 0.3, e₀ = 1.25) has an effective vertical stress of 120 kPa at its mid-depth. A wide fill raises the vertical stress in the clay by 95 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.
Consolidation settlement worksheet with answers
A 2.5 m thick layer of normally consolidated clay (Cc = 0.45, e₀ = 1.15) has an effective vertical stress of 45 kPa at its mid-depth. A wide fill raises the vertical stress in the clay by 125 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.
A 4.5 m thick overconsolidated clay layer has Cc = 0.35, Cr = 0.03 and e₀ = 0.7. At its mid-depth the effective vertical stress is 45 kPa and the preconsolidation pressure is 75 kPa. A new building adds 50 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A 5.5 m thick overconsolidated clay layer has Cc = 0.2, Cr = 0.03 and e₀ = 1. At its mid-depth the effective vertical stress is 55 kPa and the preconsolidation pressure is 95 kPa. A new building adds 30 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A clay layer 9.5 m thick has a coefficient of consolidation cv = 2 m²/year. It lies between two sand layers, so water drains out at the top and the bottom. For 70% average consolidation the time factor is Tv = 0.403. How many years t does the layer take to reach 70% consolidation?
A clay layer 5.5 m thick has a coefficient of consolidation cv = 5 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?
Answer key
- 1. S = 101.3 mm
- 2. S = 302 mm
- 3. S = 112.7 mm
- 4. S = 15.6 mm
- 5. t = 4.546 years
- 6. t = 3.43 years
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