Concrete Column PMM Designer

Easily design concrete columns for biaxial bending with this advanced tool from efficalc. Define your column geometry and load cases, then the tool will generate a detailed 3D PMM plot, demand-to-capacity ratios, and a comprehensive report featuring 2D P-M plots for each load case.

Concrete column in biaxial bending with P-M diagram

Design your column here:

Use the interactive form below to design your column for bi-directional flexure. View or print the calculation report using the icons in the "Results" section.

  1. ACI 318-19 controls the design
  2. Reinforcement is non-prestressed
  3. Lap splices of longitudinal reinforcement are in accordance with ACI 318-19 Table 10.7.5.2.2
  4. Strain in concrete and reinforcement is proportional to distance from the neutral axis, per ACI 318-19 22.2.1.2

Inputs

Description
Name
Value (units)
Column section width (x dimension)

Column section height (y dimension)

Longitudinal rebar size (Imperial)
Longitudinal rebar cover

Cover is to bar center or bar edge (clear cover)
Transverse reinforcement type
Number of bars on the top/bottom edges
Number of bars on the left/right edges
Concrete strength

Steel strength

Pu (kip)

Mux (kip-ft)

Muy (kip-ft)

Show in Calc Report (yes/no)

1

x y 24.00" 36.00" 2.00" (6)#8 x-direction, E.S. (8)#8 y-direction, N.S.

Section of Column

Results

O.K.

O.K.

trace 0trace 2trace 3trace 4trace 5trace 6trace 7trace 8trace 9trace 10trace 11trace 12trace 13trace 14trace 15trace 16trace 17trace 18trace 19trace 20trace 21trace 22trace 23trace 24trace 25trace 26trace 27trace 28trace 29trace 30trace 31trace 32trace 33trace 34trace 35trace 36trace 37trace 38trace 39trace 40trace 41trace 42trace 43trace 44trace 45trace 46trace 47trace 48trace 49trace 50trace 51trace 52trace 53trace 55trace 57ΦMₙₓΦMₙᵧΦPₙ
3D PMM Capacity Plot

What you get:

  • Instant Results: Simply enter the column properties and load combinations to receive an immediate and accurate design strength evaluation in accordance with ACI 318-19.
  • Detailed Calculation Report: Your calculation comes with a free professional-quality calculation report which details every calculation step, making it simple to review, verify, and submit in a design package.
  • Customization: You can change any part of these calculations and make it your own! Simply copy or save this template below and edit it in any way that suits your project.
  • Open Source: This calculator is 100% built with our open-source Python calculations library, efficalc. You can make your own calculations just like this on the website, or in a local Python environment and integrate them with your other Python workflows.

How it works:

  • Capacity Calculation: Column capacity is calculated by the exact capacity method. In contrast to approximate methods such as the Bresler load contour method and the Bresler reciprocal load method, the exact capacity method calculates the column’s axial and moment capacity at the particular eccentricity angle at which the load is applied.
  • PMM Diagrams: The PMM surface describes the capacity of the column in P, Mx, My (any load case falling inside the PMM surface is within capacity, and any load case falling outside the PMM surface exceeds capacity). The PMM diagrams created by this program comprise a mesh of calculated capacity points which are evenly spaced in both axial load and eccentricity angle.
  • DCRs: The DCRs reported are PM Vector DCRs, defined as the ratio of the length of the demand vector (in PMM space) to the length of a parallel vector beginning at the origin and continuing until it reaches the PMM surface.
  • Capacity Point Search: To calculate capacity points both for DCRs and for PMM diagrams, the program uses an iterative method in which the two parameters determining capacity (the neutral axis angle and neutral axis depth) are varied until the target capacity point is reached.
  • P-M Diagrams: These compare each load case (axial force and resultant moment) against the column's P-M capacity at the same direction of loading. These are generated by taking a cut of the PMM surface at a given eccentricity angle.

    • More documentation is available at this calculation's README here.

Designed with modern engineers in mind, efficalc will not only speed up your design process but also integrate seamlessly with today's automated and data-driven engineering environments.

We value your feedback and are always looking for ways to enhance our tools. Reach out to us with the contact button () to the right or at github.com/youandvern/efficalc/issues anytime!

Save or copy this template:

This calculator is too large or complex to run on the efficalc platform right now. To save, change, and/or run this calculation on your own computer, you can find it at github.com/youandvern/efficalc/tree/main/examples.

Note: you can make suggestions for improvements to this code at github.com/youandvern/efficalc/issues or by sending us a message with the contact button.

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Disclaimer: This calculator is provided as a free tool to assist professionals and does not offer any warranties or guarantees regarding its use or the results. All calculations and engineering decisions must be reviewed and approved by a licensed professional engineer who will take responsibility for their application. Efficalc and its affiliates disclaim any responsibility for the accuracy or adequacy of any design resulting from the use of this calculator. Users agree to indemnify and hold harmless Efficalc from any claims, damages, or liabilities that may arise from the use of this calculator or its outputs. This calculator is not a substitute for professional judgment.