A 4.5 m thick layer of normally consolidated clay (Cc = 0.5, e₀ = 1) has an effective vertical stress of 45 kPa at its mid-depth. A wide fill raises the vertical stress in the clay by 130 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 3 m thick normally consolidated clay layer (γsat = 19 kN/m³, Cc = 0.5, e₀ = 0.7) lies below 3.5 m of sand (γ = 19 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 150 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.
A 6 m thick overconsolidated clay layer has Cc = 0.4, Cr = 0.06 and e₀ = 0.85. At its mid-depth the effective vertical stress is 65 kPa and the overconsolidation ratio is OCR = 2.5. A new building adds 200 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A 2 m thick overconsolidated clay layer has Cc = 0.35, Cr = 0.06 and e₀ = 0.85. At its mid-depth the effective vertical stress is 90 kPa and the preconsolidation pressure is 170 kPa. A new building adds 70 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.
A clay layer 3 m thick has a coefficient of consolidation cv = 5 m²/year. It lies between two sand layers, so water drains out at the top and the bottom. For 50% average consolidation the time factor is Tv = 0.197. How many years t does the layer take to reach 50% consolidation?
A clay layer 7.5 m thick has a coefficient of consolidation cv = 0.5 m²/year. It lies between two sand layers, so water drains out at the top and the bottom. 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 = 663.6 mm
- 2. S = 403.8 mm
- 3. S = 353 mm
- 4. S = 16.21 mm
- 5. t = 0.08865 years
- 6. t = 5.541 years
Full step-by-step solutions: practise this topic on examproblems.com.