> For the complete documentation index, see [llms.txt](https://docs.enercalc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.enercalc.com/e3d-user-manual/interface/toc175916526/concrete/rc-design-criteria/toc161393951.md).

# RC Column Design Criteria

How to define and assign reinforced concrete column design criteria including bracing, ties, and bar layout.

Concrete Design > RC Design Criteria > RC Column Design Criteria prompts you with the following dialog.

![](https://560001759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FWNe8U6EBBBdUJHdb2X9G%2Fuploads%2Fgit-blob-c1148bcf07e0663979a85b208356d4804d231ccf%2FConcrete%20Column%20Design%20Criteria.png?alt=media)

It allows you to define and/or assign different design criteria to selected concrete columns. An ID is assigned automatically to each design criterion by the program and may not be changed. You may assign a label with 127 maximum characters to each design criterion. The column design criteria include:

* Sway flags in x and y directions.
* Unbraced lengths in x and y directions. You may enter zero if you want the program to use the member lengths as the unbraced lengths.
* Effective length factors in x and y directions.
* Number of tie legs.
* Tie bar size.
* Concrete cover to the outside surface of ties. Since different longitudinal bar sizes may be used during automatic section generation, the program computes concrete cover to bar center based on the following formula: “cover to tie” + “tie diameter” + one half of “longitudinal bar diameter” *Note: This is different from concrete cover for beams.*
* Start and end bar trial sizes for section generation.
* Bar layout:

All Patterns: Patterns will be tried with bars placed on Major Sides, Minor Sides, and Equal Sides of the section as described below.

Major Sides: Bars will be placed only on the sides parallel to the section major axis.

Minor Sides: Bars will be placed only on the sides parallel to the section minor axis.

Equal Sides: Bars will be distributed equally on all sides.

* Confinement: Confining reinforcement can be either tied or spiral. Spiral applies to circular sections only.

You may add one or more criteria by clicking the “New Rows” button. You may also print all design criteria in the list by clicking the “Print” button. The “Assign active criteria to selected members” checkbox may be used to assign the active column design criterion to selected columns. The active criterion refers to the one that currently has focus in the list in the dialog. In order for column design criteria assignments to take place, columns must be selected beforehand.

The program always has a default column design criterion labeled “Default”. You may not delete this criterion or change its label. You may however change its properties.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.enercalc.com/e3d-user-manual/interface/toc175916526/concrete/rc-design-criteria/toc161393951.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.