A 2.5 m thick layer of normally consolidated clay (Cc = 0.25, e₀ = 1.3) has an effective vertical stress of 55 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.
Consolidation settlement worksheet with answers
A 5 m thick layer of normally consolidated clay (Cc = 0.3, e₀ = 1.35) has an effective vertical stress of 50 kPa at its mid-depth. A wide fill raises the vertical stress in the clay by 145 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.
A 2.5 m thick overconsolidated clay layer has Cc = 0.25, Cr = 0.04 and e₀ = 1.05. At its mid-depth the effective vertical stress is 65 kPa and the overconsolidation ratio is OCR = 2.5. A new building adds 120 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A 7 m thick overconsolidated clay layer has Cc = 0.5, Cr = 0.06 and e₀ = 0.75. At its mid-depth the effective vertical stress is 80 kPa and the preconsolidation pressure is 130 kPa. A new building adds 110 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A clay layer 5 m thick has a coefficient of consolidation cv = 3 m²/year. It lies on impervious rock, with sand above it, so water drains out only at the top. For 60% average consolidation the time factor is Tv = 0.287. How many years t does the layer take to reach 60% consolidation?
A clay layer 2.5 m thick has a coefficient of consolidation cv = 1.5 m²/year. It lies on impervious rock, with sand above it, so water drains out only at the top. For 50% average consolidation the time factor is Tv = 0.197. How many years t does the layer take to reach 50% consolidation?
Answer key
- 1. S = 139.9 mm
- 2. S = 377.3 mm
- 3. S = 36.58 mm
- 4. S = 380.2 mm
- 5. t = 2.392 years
- 6. t = 0.8208 years
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