Rectangular Footing [SIG]
Footing
Substructure: Choose the substructure element associated with the footing, such as columns. The center of the selected element will be utilized for positioning the footing.
Footing Width: The width of the footing refers to the measurement in the transverse direction along the PGL.
Footing Length: The parameter specifies the footing length in the longitudinal direction.
Thickness: The thickness of the footing is also employed to define the shell element thicknesses in the analytical model.
Longitudinal Offset: Employed to determine the position of the footing. Longitudinal offset along the Projected Grade Line (PGL), where 0 refers to the center point of the substructure above.
Transverse Offset: This parameter can be used to specify the location of the footing's center, where a value of 0 places it at the center of the chosen substructure. A positive value will offset the footing to the right, and a negative value will offset it to the left when looking up-station along the PGL.
The positive direction of the Y-axis will be to the left when looking upstream along the PGL. However, based on the requests of engineers who have been using OpenBrIM for their bridge projects, positive transverse offset values will indicate the right-hand side when looking upstream along the PGL. This distinction should be taken into account when defining the location of bridge elements using transverse offset values (where positive transverse offset indicates the right side), as well as when making definitions related to FEM and loading (where positive Fy indicates the left side along the PGL).
Material: Material of the footing.
Rotation: This parameter is utilized to rotate the rectangular footing, with 0 indicating that it is perpendicular to the PGL.
FEM
Generate FEM ? [Yes/No]: Setting the "Generate FEM" parameter to "No" can disable the analytical representation of the pile.
Rigid Section: A rigid section is employed to establish rigid line elements that connect the footing to pier columns or piles. Column connections are established using five rigid elements to distribute pier forces to the footing from five distinct locations (center, top right, top left, bottom left, and bottom right) rather than a single point, which would result in unrealistic high stress concentrations. When the user assigns different sections, the locations of the rigid lines and the footing mesh adapt accordingly.
Mesh Size: The maximum length of the shell elements representing the footing.
Min Number of Strips in Longitudinal Direction: The longitudinal direction corresponds to the direction that is along the length of the footing. The number of strips is employed to extract major axis bending moment results from shell elements using the fecomposite approach for design purposes. Essentially, it consolidates the forces of shell elements at their centers of gravity. If 1 is selected, the design will utilize the combined forces of all shell elements.
Min Number of Strips in Transverse Direction: The longitudinal direction corresponds to the direction that is along the width of the footing. The number of strips is employed to extract major axis bending moment results from shell elements using the fecomposite approach for design purposes. Essentially, it consolidates the forces of shell elements at their centers of gravity. If 1 is selected, the design will utilize the combined forces of all shell elements.
As per AASHTO C5.12.8.4, the moment of the forces acting on one side of the vertical plane passing through the entire section should be used; therefore, using one strip is suggested