Column Definition Dialog Box

The Column Definition dialog box allows you to create, modify, or delete user-defined, nonstandard column shapes. To open this dialog box, click the Piers button on the Geometry tab to open the Pier and Column Definitions dialog box and then click the Column Type button.

The user can specify either the gross or the effective (fraction of gross) moment of inertia of the column for analysis.

If a column does not have one of the standard sections or it is nonprismatic, this dialog box allows you to define the shape by specifying the sections, including linear and/or parabolic variations along its length. Each user-defined column is made of one of the basic shapes identified in the graphics window and has at least a top and bottom section. Additional sections can be defined within the length of the column by giving its distance from the section above it and its dimensions. All parameters that define the column section will be varied along the length between sections. User-defined columns can be referenced in any pier and can be referenced more than one time. Columns automatically locate the top and bottom section, depending on the type of substructure defined. The length of the lowest segment is determined from the total column length given in the Piers and Column Definitions dialog box.

Note: Standard, prismatic column sections can be easily entered into the Pier and Column Definitions dialog box.

Selecting an Existing Column

Perform the following steps to select and/or rename an existing column:

Select the desired column from the Column Name drop-down list.
Double-click in the existing column name and enter the new name.

Adding Columns

Any number of column types can be defined (added) and referenced and located at any pier using the Pier and Column Definitions dialog box. Note that not all column types have to be referenced or located. Perform the following steps to add a new column:

Click the New button under the Column Name field.
Enter the name of the column in the Column Name field.

Enter the column values in the grid. A definition for each parameter is available below.

Setting	Description
Circular	Circular column of diameter "H".
Rectangular	Rectangular column with sides "H" and "V", where H is measured along the plane of the bent.
Rect-Fillet	Rectangular column with rounded corners of radius "R".
Rect-Chamfer	Rectangular column with chamfered corners of dimension "C".
Rect-Bevel	Rectangular column with beveled corners with dimensions "X" and "Y".
General	General shape column defined using cross sectional area and Izz and Iyy, where Izz is about the axis of the pier.

Enter the column values in the grid. A definition for each parameter is available below.

Deleting Columns

A user-defined column type can be deleted at any time. Columns will be deleted from piers that reference the deleted column and piers will be deleted if the entire pier is made up from the deleted column. A warning message displays and asks you to confirm or cancel the deletion.

Select the column you want to delete from the Column Name field.
Click the Delete button to remove the selected column.

Selecting the Section Type

Once a column type is displayed, sections can be added at any time. There are no limits on the number of sections allowed in a column. However, if you change a column shape (e.g., from circular to rectangular), all intermediate section information is lost.

All column sections must be of the same type. By default, a column has a top and bottom section. The top section is at the soffit of the superstructure if the is in a pier with an integral cap or is at the base of a drop-cap pier. The bottom section is placed automatically at the depth defined by the column length specified when it is in a pier definition. Refer to the Technical Discussion below for more information.

Perform the following steps to add a new section to an existing column:

Select the column you want to modify from the Column Name field.
In the grid, select the section you want to add to by clicking on its row. A blue arrow displays on the left side of the grid to mark the selection.
Click the Add Section button.
Enter the column values in the grid. A definition for each parameter is available below.

Copying Sections

CIP RC/PT Girder places a copy of the selected column section after the selected section. Perform the following steps to add a new column section to an existing column:

Deleting Sections

Select the column you want add a new column section to in the Column Name field.
In the grid, select the section you want to add a new section after. A blue arrow displays on the left side of the grid to mark the selection.
Click the Add Section button to add a copy of the selected section.

By default, a column has a top and bottom section. Top and/or bottom sections cannot be deleted. Perform the following steps to delete a section from an existing column:

Note: You will not be asked to confirm this delete command nor can this deletion be undone.

Select the column you want to delete a section from in the Column Name field.
In the grid, select the section you want to delete. A blue arrow displays on the left side of the grid to mark the selection.
Click the Delete Section button to remove the selected section.

Grid Definitions

Setting

Description

Distance

The distance from the top of the column.

The column section width (or diameter). The width is measured along the centerline of the pier that the column is placed in.

The column section depth. The depth is measured perpendicular to the centerline of the pier that the column is placed in.

R, C or X

The column fillet radius, chamfer, or bevel x-dimension.

The column section bevel y-dimension.

Variation

Select the variation method to use for the particular section from the drop-down list.

Setting	Description
Linear	Section parameters are linearly varied from the last location where the parameter was specified.
Constant	Section changes begin instantaneously starting from this location.
Parabolic	Section parameters are varied parabolically from the last location where the parameter was specified. The parabolic form is where the parabola has a zero slope (i.e., horizontal) at the start of the parabola (located at the last location the parameter was specified).

Technical Discussion

The Column Definition dialog box is used to define column types different than the five available standard shapes. Any nonprismatic column type must be defined using the Column Definition dialog box.

Nomenclature

Setting	Description
Add Section	Add a section to the column.
Circular	Circular column of diameter "H". (Column Section Type)
Column Name	The name of a column definition.
Constant	Section changes begin instantaneously starting from this location. (Section Variation Method)
Delete Section	Delete a section from the column.
Delete	Delete a column definition.
Distance	The distance from the top of the column.
Front	View the front side of the column.
General	General shape column defined using cross sectional area and Izz and Iyy, where Izz is about the axis of the pier. (Column Section Type)
H	The column section width (or diameter). The width is measured along the centerline of the pier that the column is placed in.
Linear	Section parameters are linearly varied from the last location where the parameter was specified (Section Variation Method).
New	Add a new column definition.
Parabolic	Section parameters are varied parabolically from the last location where the parameter was specified (Section Variation Method).
R, C, or X	The column's fillet radius, chamfer, or bevel-X dimensions (for use with Rect-Fillet, Rect-Chamfer, and Rect-Bevel columns only).
Rectangular	Rectangular column with sides "H" and "V", where H is measured along the plane of the bent. (Column Section Type)
Rect-Bevel	Rectangular column with beveled corners with dimensions "X" and "Y". (Column Section Type)
Rect-Chamfer	Rectangular column with chamfered corners of dimension "C". (Column Section Type)
Rect-Fillet	Rectangular column with rounded corners of radius "R". (Column Section Type)
Section	View the current section of the column.
Section Type	The column section type.
Side	View the side of the column.
V	The column section depth. The depth is measured perpendicular to the centerline of the pier that the column is placed in (not used with circular column types).
Variation	The variation method to use for the particular section.
Y	The column's bevel-Y dimensions (for use with Rect-Bevel columns only).