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Terzaghi Shallow Foundation Bearing Capacity Calculator

Terzaghi bearing capacity equation determines the ultimate load intensity a soil foundation can support before catastrophic general shear failure occurs.

Calculated Result
412.8 kPa

Allowable Bearing Pressure

Ultimate Capacity (q_ult)

1238.3 kPa

Factors (N_c, N_q, N_γ)

31.6, 17.8, 14.6

Safety Factor applied

3.0x

Calculation Breakdown

  1. q_ult = c·N_c + γ·D_f·N_q + 0.5·γ·B·N_γ1238.3 kPa
  2. q_all = q_ult / FS412.8 kPa

What Is the Terzaghi Shallow Foundation Bearing Capacity Calculator?

Terzaghi bearing capacity equation determines the ultimate load intensity a soil foundation can support before catastrophic general shear failure occurs.

This calculator evaluates bearing capacity factors Nc, Nq, Nγ, ultimate bearing capacity q_ult, and safe allowable soil pressure based on factor of safety.

How Does the Terzaghi Shallow Foundation Bearing Capacity Calculator Work?

The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.

Terzaghi Shallow Foundation Bearing Capacity Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

q_ult = c · N_c + q · N_q + 0.5 · γ · B · N_γ, q_all = q_ult / FS

Terzaghi general shear failure formula combining cohesion, surcharge overburden q = γ·Df, and footing self-weight wedge components.

How to Use the Terzaghi Shallow Foundation Bearing Capacity Calculator

  1. Enter your primary measurements in the input fields above.
  2. Select your preferred units (e.g. metric or imperial) if applicable.
  3. Review or adjust operational assumptions such as field efficiency.
  4. Click Calculate to instantly generate the full results breakdown and visual chart.
  5. Use the Reset button at any time to clear the form and test a new scenario.

Step-by-Step Example Calculation

2m wide strip footing embedded 1.5m in cohesive-frictional soil (c = 15 kPa, φ = 28°)

Input Values:

footingWidthBM:2
embedmentDepthDfM:1.5
soilCohesionKpa:15
soilFrictionAngleDeg:28
soilUnitWeightKnPerM3:18.5
factorOfSafety:3
Worked Steps: Nc = 31.6, Nq = 17.8, Nγ = 15.0 yielding ultimate capacity q_ult = 1,173 kPa and allowable q_all = 391 kPa.

Understanding Your Result

Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.

Factors That Affect the Result

Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.

When Should You Use This Calculator?

Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.

Assumptions & Limitations

  • Geotechnical Engineering
  • Foundation Engineering
  • Civil Engineering

Frequently Asked Questions

Calculation Accuracy & Reference Note

This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.

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