Single Pile Capacity
Estimate vertical capacity Q of a single pile from end bearing qb, tip area Ab and side friction (perimeter u, length L, fs).
Inputs
Formula
Fundamentals
Estimate vertical capacity Q of a single pile from end bearing qb, tip area Ab and side friction (perimeter u, length L, fs).
This tool computes Single Pile Capacity from the formula: Q = qb·Ab + u·L·fs
History
Soil and structural mechanics were systematised in the 19th century, supporting modern civil design.
Engineering applications
Used for retaining, foundation and structural member design.
Glossary
| End bearing qb | Input parameter |
| Tip area Ab | Input parameter |
| Perimeter u | Input parameter |
| Capacity Q | Output result |
How to use
- Fill in End bearing qb, Tip area Ab, Perimeter u, Embedded L, Shaft friction fs in the Inputs section (watch the unit on each field).
- Click Calculate; the tool evaluates the formula shown above.
- Read Capacity Q in the results area.
Formula · Worked Example · Knowledge
Formula
核心计算关系：Q = qb·Ab + u·L·fs
输入变量：
- End bearing qb
qb— kPa - Tip area Ab
Ab— m² - Perimeter u
u— m - Embedded L
L— m - Shaft friction fs
fs— kPa
输出结果：
- Capacity Q
Q— kN
假设/适用：Earth pressure uses Rankine/Coulomb active assumptions; passive & surcharge handled separately.
Worked Example
根据公式 Q = qb·Ab + u·L·fs，取 End bearing qb = 2,000 kPa；Tip area Ab = 0.5 m²；Perimeter u = 2.5 m；Embedded L = 10 m；Shaft friction fs = 40 kPa。
代入计算得：Capacity Q = 2,000 kN。
Key Points
- Earth pressure uses Rankine/Coulomb active assumptions; passive & surcharge handled separately.
- Check both strength and stability (overturning, sliding).
- Support reactions from static equilibrium; continuous structures need force/displacement method.
Parameters
Inputs
| Parameter | Symbol | Unit | Default |
|---|---|---|---|
| End bearing qb (kPa) | qb | kPa | 2000 |
| Tip area Ab (m²) | Ab | m² | 0.5 |
| Perimeter u (m) | u | m | 2.5 |
| Embedded L (m) | L | m | 10 |
| Shaft friction fs (kPa) | fs | kPa | 40 |
Outputs
| Result | Symbol | Unit |
|---|---|---|
| Capacity Q | Q | kN |
Applications
- Simply-supported/cantilever reactions
- Structural equilibrium analysis
- Shear & moment distribution