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.

New worksheetPractise online with hints

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 = 80 kPasandγ = 18 kN/m³6 mclayγsat​ = 19 kN/m³Cc​ = 0.15, e0​ = 13 mwater tableX

A 3 m thick normally consolidated clay layer (γsat = 19 kN/m³, Cc = 0.15, e₀ = 1) lies below 6 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 80 kPa. Treat the layer as one sublayer with the stresses at its mid-depth. Find the primary consolidation settlement S in mm.

sand: Hs = 6 m, γ = 18 kN/m³clay: H = 3 m, γsat = 19 kN/m³γw = 9.81 kN/m³Cc = 0.15e0 = 1Δσ = 80 kPa
S = mm
2.Easy
Δσ = 95 kPasandγ = 17 kN/m³4 mclayγsat​ = 17.5 kN/m³Cc​ = 0.3, e0​ = 0.655 mwater tableX

A 5 m thick normally consolidated clay layer (γsat = 17.5 kN/m³, Cc = 0.3, e₀ = 0.65) lies below 4 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 95 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 m, γ = 17 kN/m³clay: H = 5 m, γsat = 17.5 kN/m³γw = 9.81 kN/m³Cc = 0.3e0 = 0.65Δσ = 95 kPa
S = mm
3.Medium
Δσ = 130 kPasandclayCc​ = 0.2, Cr​ = 0.05e0​ = 0.6σ′0​ = 45 kPaOCR = 37 mwater table

A 7 m thick overconsolidated clay layer has Cc = 0.2, Cr = 0.05 and e₀ = 0.6. At its mid-depth the effective vertical stress is 45 kPa and the overconsolidation ratio is OCR = 3. A new building adds 130 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.

H = 7 mCc = 0.2Cr = 0.05e0 = 0.6σ′0 = 45 kPaOCR = 3Δσ = 130 kPa
S = mm
4.Medium
Δσ = 25 kPasandclayCc​ = 0.2, Cr​ = 0.06e0​ = 1.1σ′0​ = 90 kPaσ′p​ = 130 kPa7.5 mwater table

A 7.5 m thick overconsolidated clay layer has Cc = 0.2, Cr = 0.06 and e₀ = 1.1. At its mid-depth the effective vertical stress is 90 kPa and the preconsolidation pressure is 130 kPa. A new building adds 25 kPa of vertical stress at mid-depth. Find the primary consolidation settlement S in mm.

H = 7.5 mCc = 0.2Cr = 0.06e0 = 1.1σ′0 = 90 kPaσ′p = 130 kPaΔσ = 25 kPa
S = mm
5.Hard
sandclayH = 5 m5 mimpervious rockwater table

In a laboratory oedometer test, a clay specimen 20 mm thick, drained at the top and bottom, reaches 50% consolidation in 15 min. In the field the same clay forms a layer 5 m thick. It lies on impervious rock, with sand above it, so water drains out only at the top. How many days t does the field layer take to reach 50% consolidation?

hlab = 20 mmtlab = 15 minH = 5 mfield: single drainage
t = days
6.Hard
sandclayH = 6.5 mcv​ = 0.5 m²/year6.5 msandwater table

A clay layer 6.5 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?

H = 6.5 mcv = 0.5 m²/yearU = 50%Tv = 0.197double drainage
t = years

Answer key

  1. 1. S = 49.34 mm
  2. 2. S = 290.9 mm
  3. 3. S = 203 mm
  4. 4. S = 22.81 mm
  5. 5. t = 2604 days
  6. 6. t = 4.162 years

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