Showing posts with label Soil Mechanics. Show all posts
Showing posts with label Soil Mechanics. Show all posts

Saturday, December 27, 2025

Square footing, B = 2 m, sandy soil, γ = 18 kN/m³, φ = 30°, Df = 1.5 m, c = 0. Find ultimate bearing capacity.

 Square footing, B = 2 m, sandy soil, γ = 18 kN/m³, φ = 30°, Df = 1.5 m, c = 0. Find ultimate bearing capacity.

Solution:

qu=γDfNq+0.4γBNγq_u = \gamma Df N_q + 0.4 \gamma B N_\gamma
  • Nq18.4,Nγ22.4N_q \approx 18.4, N_\gamma \approx 22.4

qu=181.518.4+0.418222.4=858.7 kPaq_u = 18 \cdot 1.5 \cdot 18.4 + 0.4 \cdot 18 \cdot 2 \cdot 22.4 = 858.7 \text{ kPa}

Answer: 0.859 MPa

A clay layer of thickness 4 m is subjected to a uniform load of 100 kPa. Coefficient of volume compressibility m v = 0.0004 m²/kN mv​=0.0004 m²/kN. Find the immediate consolidation settlement.

 A clay layer of thickness 4 m is subjected to a uniform load of 100 kPa. Coefficient of volume compressibility 

mv=0.0004 m²/kNm_v = 0.0004 \text{ m²/kN}. Find the immediate consolidation settlement.

Solution:

Step 1: Settlement formula

S=mvσHS = m_v \cdot \sigma \cdot H

Where:

  • SS = settlement

  • mvm_v = coefficient of volume compressibility

  • σ\sigma = applied pressure

  • HH = thickness of layer

Step 2: Substitute values

S=0.00041004=0.16 m=160 mmS = 0.0004 \cdot 100 \cdot 4 = 0.16 \text{ m} = 160 \text{ mm}

✅ Answer: Settlement = 160 mm