Ultimate Bearing Capacity given Depth of Footing Calculator

Ultimate Bearing Capacity Formula:

\[ q_f = q_{net} + (\gamma \times D_{footing}) \]

Net Ultimate Bearing Capacity:

Unit Weight of Soil:

N/m³

Depth of Footing in Soil:

Tolerance:

Ultimate Bearing Capacity (Pa):

Tolerance Range (±5%):

1. What is Ultimate Bearing Capacity?

Definition: Ultimate Bearing Capacity is defined as the minimum gross pressure intensity at the base of the foundation at which the soil fails in shear.

Purpose: It helps engineers determine the maximum load a foundation can support before failure occurs.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ q_f = q_{net} + (\gamma \times D_{footing}) \]

Where:

\( q_f \) — Ultimate Bearing Capacity (Pa)
\( q_{net} \) — Net Ultimate Bearing Capacity (Pa)
\( \gamma \) — Unit Weight of Soil (N/m³)
\( D_{footing} \) — Depth of Footing in Soil (m)

Explanation: The net bearing capacity is adjusted by adding the product of soil unit weight and footing depth.

3. Importance of Bearing Capacity Calculation

Details: Proper calculation ensures foundation stability, prevents settlement issues, and maintains structural integrity.

4. Using the Calculator

Tips: Enter net bearing capacity in Pa, soil unit weight in N/m³, footing depth in meters, and tolerance percentage (default ±5%). All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the tolerance percentage for?
A: It provides a practical range (±%) around the calculated value to account for material variations and safety factors.

Q2: How do I determine net ultimate bearing capacity?
A: It's typically determined through soil testing or using standard values for soil types.

Q3: Does deeper footing always mean higher capacity?
A: Generally yes, as deeper footings benefit from overburden pressure, but soil properties must be considered.

Q4: What's a typical unit weight for soil?
A: Common values range from 16,000-20,000 N/m³, but varies by soil type and moisture content.

Q5: When would I change the tolerance percentage?
A: Adjust for higher precision requirements (lower %) or when working with highly variable soils (higher %).