Consolidation settlement worksheet with answers

Free printable Consolidation settlement worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
Δσ = 140 kPasandclayCc​ = 0.6e0​ = 0.65σ′0​ = 125 kPa10 mwater table

A 10 m thick layer of normally consolidated clay (Cc = 0.6, e₀ = 0.65) has an effective vertical stress of 125 kPa at its mid-depth. A wide fill raises the vertical stress in the clay by 140 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.

H = 10 mCc = 0.6e0 = 0.65σ′0 = 125 kPaΔσ = 140 kPa
S = mm
2.Easy
Δσ = 150 kPasandγ = 18 kN/m³3.5 mclayγsat​ = 18 kN/m³Cc​ = 0.6, e0​ = 1.356 mwater tableX

A 6 m thick normally consolidated clay layer (γsat = 18 kN/m³, Cc = 0.6, e₀ = 1.35) lies below 3.5 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 150 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.

sand: Hs = 3.5 m, γ = 18 kN/m³clay: H = 6 m, γsat = 18 kN/m³γw = 9.81 kN/m³Cc = 0.6e0 = 1.35Δσ = 150 kPa
S = mm
3.Medium
Δσ = 50 kPasandclayCc​ = 0.25, Cr​ = 0.06e0​ = 0.6σ′0​ = 80 kPaσ′p​ = 180 kPa4 mwater table

A 4 m thick overconsolidated clay layer has Cc = 0.25, Cr = 0.06 and e₀ = 0.6. At its mid-depth the effective vertical stress is 80 kPa and the preconsolidation pressure is 180 kPa. A new building adds 50 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.

H = 4 mCc = 0.25Cr = 0.06e0 = 0.6σ′0 = 80 kPaσ′p = 180 kPaΔσ = 50 kPa
S = mm
4.Medium
Δσ = 130 kPasandclayCc​ = 0.25, Cr​ = 0.02e0​ = 0.65σ′0​ = 45 kPaOCR = 28 mwater table

An 8 m thick overconsolidated clay layer has Cc = 0.25, Cr = 0.02 and e₀ = 0.65. At its mid-depth the effective vertical stress is 45 kPa and the overconsolidation ratio is OCR = 2. A new building adds 130 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.

H = 8 mCc = 0.25Cr = 0.02e0 = 0.65σ′0 = 45 kPaOCR = 2Δσ = 130 kPa
S = mm
5.Hard
sandclayH = 7.5 m7.5 msandwater table

In a laboratory oedometer test, a clay specimen 25 mm thick, drained at the top and bottom, reaches 50% consolidation in 8 min. In the field the same clay forms a layer 7.5 m thick. It lies between two sand layers, so water drains out at the top and the bottom. How many days t does the field layer take to reach 50% consolidation?

hlab = 25 mmtlab = 8 minH = 7.5 mfield: double drainage
t = days
6.Hard
sandclayH = 7 mcv​ = 4 m²/year7 msandwater table

A clay layer 7 m thick has a coefficient of consolidation cv = 4 m²/year. It lies between two sand layers, so water drains out at the top and the bottom. For 80% average consolidation the time factor is Tv = 0.567. How many years t does the layer take to reach 80% consolidation?

H = 7 mcv = 4 m²/yearU = 80%Tv = 0.567double drainage
t = years

Answer key

  1. 1. S = 1187 mm
  2. 2. S = 664 mm
  3. 3. S = 31.63 mm
  4. 4. S = 379.2 mm
  5. 5. t = 500 days
  6. 6. t = 1.736 years

Full step-by-step solutions: practise this topic on examproblems.com.