Consolidation Settlement
Consolidation Settlement
Saturated clay slowly squeezes out water under load and settles; the compression index predicts how much.
The settlement is S = (C_c·H/(1 + e_0))·log₁₀(σ_f/σ_0). where C_c is the compression index, H the layer thickness, e_0 the initial void ratio and σ_0, σ_f the initial and final stresses.
Inputs
C_c := 0.3=0.3
H := 5 m=5 m
e_0 := 0.9=0.9
sigma_0 := 100 kPa=100000 Pa
sigma_f := 200 kPa=200000 Pa
Apply the one-dimensional consolidation settlement equation.
S := (C_c·H/(1 + e_0))·log10(sigma_f/sigma_0)=237.66 mm
Results
Doubling the stress on this clay settles it by roughly 240 mm. The logarithm means each further load increment adds less settlement.
Assumptions & limitations
- Normally consolidated clay.
- One-dimensional (oedometer) conditions.
- Primary consolidation only.