Soil Consolidation Calculator

Complete Guide to Soil Consolidation Analysis

The Soil Consolidation Calculator predicts settlement and time rate using Terzaghi’s one-dimensional theory. Essential for foundations, embankments, and preloading. Pair with Settlement and Pile tools.

Consolidation Mechanism

Excess pore pressure dissipates → volume decrease → settlement.

Settlement Equations

NC: \[ S = \frac{C_c}{1+e_0} H \log \frac{\sigma'_0 + \Delta\sigma'}{\sigma'_0} \]

OC: \[ S = \frac{C_s}{1+e_0} H \log \frac{\sigma'_p}{\sigma'_0} + \frac{C_c}{1+e_0} H \log \frac{\sigma'_0 + \Delta\sigma'}{\sigma'_p} \]

Time Factor

\[ T_v = \frac{C_v t}{H_d^2} \]

Hd = H/2 (double), H (single)

Degree of Consolidation U

U = f(Tv) via Casagrande or approximate formulas.

Step-by-Step

  1. Determine e₀, Cc, Cs, σ'₀, σ'p
  2. Calculate final settlement S
  3. Find Hd based on drainage
  4. Compute Tv and U
  5. Settlement at time t = U × S

Example: NC Clay

e₀=0.9, Cc=0.3, H=5m, σ'₀=100 kPa, Δσ'=80 kPa, Cv=2 m²/year, t=1.5 years, double drainage:

  • S = 0.23 m
  • U ≈ 78%
  • St = 0.18 m

Cv from Lab

Coefficient of Consolidation
Clay TypeCv (m²/year)
Soft0.5–2
Medium2–5
Stiff5–10

Preloading & Surcharge

Accelerate consolidation with temporary load.

Best Practices

  • Use wick drains for thick layers
  • Monitor with piezometers/settlement plates
  • Apply secondary compression separately

Common Mistakes

  • Ignoring OCR
  • Wrong drainage path
  • Using lab Cv directly

Advanced Topics

  • 2D/3D finite element
  • Non-linear models
  • Creep effects

Conclusion

Accurate soil consolidation prevents differential settlement. Our calculator delivers instant, code-compliant results for NC and OC clays. Design safe, long-lasting foundations!

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