Pier Load Calculator

Inputs

Enter your pier, load, and footing details. Use the same units throughout.

Units

Switching units changes default material and bearing fields.

Design basis

Combination factors follow common practice templates.

Load combination

Used for Pu, Vu, and factored moments.

Pier shape

Self‑weight is computed from geometry and unit weight.

Width b (m)

Thickness t (m)

Pier height h (m)

Used as default lateral application height if not set.

Concrete unit weight (kN/m³)

Typical: 24 kN/m³ or 150 pcf.

Superstructure dead load (kN)

Additional dead load (kN)

Utilities, crash wall, bearings, etc.

Live load (kN)

Wind lateral force W (kN)

Wind height (m)

Distance from base to wind resultant.

Seismic lateral force E (kN)

Seismic height (m)

Other lateral H (earth/water/ice) (kN)

Applied with factor “H” in selected combinations.

Other lateral height (m)

Additional base moment Mx (kN·m)

Use for cap/connection moments about X.

Additional base moment My (kN·m)

Load eccentricity ex (m)

Creates moment: My += P × ex.

Load eccentricity ey (m)

Creates moment: Mx += P × ey.

Footing width B (m)

Leave 0 to skip bearing pressures.

Footing length L (m)

Allowable bearing qa (kPa)

Service check compares qmax to qa.

Example data table

Illustrative values only. Always confirm with project criteria.

Units	Shape	h	Section	D_super	L	W @ height	Footing (B×L)	Service P	Service qmax
Metric	Rect	8.0 m	1.5×1.2 m	1500 kN	900 kN	120 kN @ 8.0 m	4.0×5.0 m	≈ 1500+900+self	Use q = P/A ± M/S
Imperial	Circ	26 ft	4.0 ft dia	340 kip	200 kip	25 kip @ 26 ft	13×16 ft	≈ 340+200+self	Check against qa (ksf)

Tip: Start with service loads (D+L) to size the footing, then evaluate your governing combination.

Formula used

This tool uses simplified statics and a rectangular footing pressure model.

Pier self‑weight: W = A × h × γ, where A is cross‑section area and γ is unit weight.
Service axial: P_serv = D + L, with D = D_super + D_add + W.
Overturning from laterals: M = Σ(F × z), using each lateral force and its height z above the base.
Eccentricity moments: Mx += P × ey and My += P × ex.
Footing bearing (rectangular): q = P/A ± Mx/Sx ± My/Sy, where A = B×L, Sx = B×L²/6, Sy = L×B²/6.
No‑tension kernel check: |ex| ≤ B/6 and |ey| ≤ L/6. If violated, qmin may become negative.

This calculator is for preliminary sizing. Apply your governing code, load definitions, and sign conventions before final design.

How to use this calculator

A practical workflow for pier reactions and footing checks.

Choose units, then select LRFD or ASD to match your design approach.
Enter pier geometry and unit weight to capture self‑weight correctly.
Add vertical loads (dead and live) from your superstructure model.
Provide lateral forces and realistic application heights for overturning.
If the load is offset, enter eccentricities to include P‑Δ moments.
Enter footing plan dimensions to compute bearing pressures.
Compare service qmax to qa, then refine as needed.

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