Pier Column [SIG]
Column
Cap: The midpoint of the pier cap is utilized to designate the position of the column.
Section Data: The section of the pier column can be specified.
Section Length(Starts From Top): Input the distances for the defined section, starting from the top of the pier column. If the sections do not vary, one row is sufficient.
Start Section: The location of the start section is calculated as the sum of all previously defined rows. If it is the first row, then the starting point is the top of the pier column.
End Section: The position of the end section is determined by adding the distance defined in this row to the sum of all previously specified rows.
Transverse Offset: For Pier Column objects, the value for the transverse offset will determine the position of the Pier Column's center relative to the chosen Pier Cap's center. A negative value will offset the Pier Column to the left, while a positive value will offset it to the right when looking up-station along the PGL.
Rotation Angle: This parameter is utilized to rotate the section.
Bottom Elevation: This parameter specifies the global elevation of the bottom of the pier column. Suppose the vertical profile of the alignment is defined, and the PGL is at an elevation of 100. In that case, entering a value of -50 here will offset the bottom of the column by 150 units from the PGL elevation.
Column Height (readonly): Displays the height of the column, which is calculated based on the input values of the 'Cap' parameter and the 'Bottom Elevation' parameter.
Top Elevation (readonly): Displays the global elevation of the top of the pier column, calculated based on the Cap's elevation.
Section Type [Straight-Tapered/Circular-Parabolic]: This parameter allows users to select the column section type:
Straight-Tapered : Uses traditional station-dependent section definitions where sections can vary linearly along the column height. This is the standard method for prismatic or tapered columns.
Circular-Parabolic : Enables non-prismatic section definitions with circular or parabolic variation parameters. This method allows for complex geometric variations along the column height using station-dependent variation functions.
Circular-Parabolic Variation
Circular-Parabolic Section: When Section Type is set to 'Circular-Parabolic', this parameter becomes active. Users can define a section with variation parameters that control how the section geometry changes along the column height. The section definition includes:
Base section geometry defined in the section editor
Variation parameters (e.g., parabola, linear) applied to section dimensions
Station-dependent ranges specifying where variations occur
Variation direction parameter (0=X, 1=Y, 2=Z) indicating the axis along which variation is applied
Circular-Parabolic Refinement: This parameter controls the mesh density for non-prismatic columns. It specifies the maximum length (in project units) of segments used to discretize the column for 3D visualization and analysis. A smaller value creates more segments, resulting in smoother geometric representation of curved or tapered sections. This refinement affects:
3D visualization accuracy for parabolic geometries
Number of intermediate sections generated along column height
Precision of section property calculations at various elevations
FEM
Cap Connection [Rigid/Pin/Rx Free/Ry Free/Rx and Ry Free]: The connection of the column to the substructure (cap) above can be defined by the parameter that offers multiple options:
Rigid: A Rigid connection assumes full moment transfer between the column and the substructure, meaning the connection resists rotation and ensures stiffness.
Pin: A Pin connection allows for rotational freedom, implying no moment is transferred, and the connection mainly resists vertical and horizontal forces.
Rx Free: This option allows the column to freely rotate about the X-axis (horizontal axis), while the connection resists moment transfer in the other directions.
Ry Free: This option allows the column to freely rotate about the Y-axis (vertical axis), while the connection resists moment transfer in the other directions.
Rx and Ry Free: This option allows the column to freely rotate about both the X-axis and Y-axis, meaning no moments are transferred in either direction, and the connection mainly resists forces in those directions.
Additional Break Points: Break points can be added to include additional nodes at various positions. The distance is inputted from the top of the pier column. In some scenarios, users enter collision loads on the pier column as a point load. If there is no node defined at that precise location, the load is distributed to the nearest nodes based on their distance. However, in these instances, the user's objective is to apply the collision force from one particular location. Thus, creating a node at the intended location can fulfill this requirement.
Generate FEM? [Yes/No]: Setting the "Generate Fem" parameter to "No" can disable the analytical representation of the pier.
Bottom Fixity [Fixed/Stiffness Matrix]: The Bottom Fixity of the pier column can be defined with one of the following options: Fixed: This assumes the base of the pier column is fully restrained, resisting all translations and rotations.
If piles, drilled shafts, or footings are defined at the bottom of this column If you choose fixed support and then deactivate the FEA for the pier footing and piles, a fixed support will be introduced at the bottom of the column, as shown below.
Choosing the fixed support and then constructing footing and pile objects and activating their FEA will deactivate the fixed support. Instead, rigid connection elements will be defined from the bottom of column to the footing, based on the column section extents, as shown with the red lines in the screenshot below. 
Stiffness Matrix: The bottom fixity is adjusted based on a defined stiffness matrix, allowing for partial restraint, depending on the stiffness values assigned.
6x6 Stiffness Matrix: If the Stiffness Matrix option is chosen, the 6x6 stiffness matrix can be specified. This matrix defines the resistance in three translational and three rotational degrees of freedom:
Tx, Ty, Tz: Translational stiffness values along the X, Y, and Z axes.
Rx, Ry, Rz: Rotational stiffness values about the X, Y, and Z axes.
By adjusting these parameters, the model can simulate varying degrees of support flexibility at the base of the pier column, providing more realistic behavior depending on the structure's design and foundation conditions.
Mesh Size: The mesh size parameter can be utilized to set the maximum distance for a single finite element line.
Pushover
Generate Top Hinge [NO/YES]: If this parameter is set to 'YES', pushover-related definitions can be specified for the column. If 'NO' is selected, the parameters related to pushover in this section will be Not Applicable (N/A).
Top Hinge Property: A previously defined hinge property (from Properties > Pushover) can be assigned to the respective section to define the properties of the top hinge.
Top Hinge Length: Specifies the length of the top hinge, determining the region of the column over which the hinge behavior will be applied.
Generate Bottom Hinge [NO/YES]: If this parameter is set to 'YES', pushover-related definitions for the bottom of the column can be specified. If 'NO' is selected, the parameters of this section will be Not Applicable (N/A).
Bottom Hinge Property: A previously defined hinge property (from Properties > Pushover) can be assigned to the respective section to define the properties of the bottom hinge.
Bottom Hinge Length: Specifies the length of the bottom hinge, defining the region of the column where the hinge behavior will apply.
Hinges are located at the midpoint of the hinge length from their respective faces (top face for top hinge, bottom face for bottom hinge). Hinge positions are displayed below.
Quantities
Bottom Surface Area: The surface area of the section assigned to the bottom of the pier column is calculated and presented to the user in this column.
Top Surface Area: The surface area of the section assigned to the top of the pier column is calculated and presented to the user in this column.
Side Surface Area: The surface area of the sides of the pier column is calculated and presented to the user in this column.
Cross Section Perimeter (Min): The minimum cross-section perimeter assigned to the element is calculated and presented to the user in this column.
Cross Section Perimeter (Max): The maximum cross-section perimeter assigned to the element is calculated and presented to the user in this column.
Volume: The volume of the pier column, based on the definitions provided by the user, is calculated and presented to the user in this column.
Weight: Based on the defined geometry and material properties of the element, the weight of the modeled element is calculated and presented to the user in this column.
Height: The height of the column is presented to the user in this column.
Cross Section Min Width: The minimum width of the cross-section assigned to the element is calculated and presented to the user in this column.
Cross Section Max Width: The maximum width of the cross-section assigned to the element is calculated and presented to the user in this column.
Cross Section Min Height: The minimum height of the cross-section assigned to the element is calculated and presented to the user in this column.
Cross Section Max Height: The maximum height of the cross-section assigned to the element is calculated and presented to the user in this column.
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