Girder Midspan

This page allows users to define and manage prestressing strand properties and debonding configurations at the girder's midspan.

Girder Cross-Section Display

• Shows a graphical representation of the girder's cross-section.

• Move (M): Move strand.

• Reset Draping: Reset all strand to their original location.

• Low Point Drape (L): Drape all strands to the lowest available strand template location.

• Clustered Point Drape (C): Drape strands to the same X, Y points.

• Stacked Drape (S): Drape strands to the lowest available template point, stacking them 1 strand diameter apart.

• Debond Strand (CTRL+D): Applies debonding to the selected strand. As shown with markers in the cross-section display.

• Removing Debonding (CTRL+R): Removes debonding from the selected strand.

• Zoom Extents (Z): Adjusts the view to fit the entire girder cross-section within the display window. Use this option for a quick reset of the visual zoom level.

• Window Zoom (W): Allows you to zoom into a specific area of the cross-section by clicking and dragging to create a selection box. This tool is useful for detailed work.

• Pan Image (P): Lets you move the cross-section display within the window. Click and drag to adjust the view without changing the zoom level.

Debonding Lengths

• Selected Length: Displays the currently chosen debonding length.

• Icons denote debonded strands in the cross-section.

  • Add: Add a new debonding length.

  • Remove: Remove the selected debonding length.

  • Copy: Copy the selected debonding strands.

Draping Properties

• Selection Mode: Allows selecting individual strands on the graphical display.

• Relative Location: Specifies the location where the draping method is applied, relative to the girder's geometry.

Strand Auto Design

This interface is designed to automate the configuration of strands and their draping properties for efficient girder design.

Eriksson Girder can automatically design either a straight pattern or a draped pattern. In either case, strands are added to the pattern until stresses are within acceptable limits. If a pattern can be found that satisfies stresses, then flexural strength is checked. If both stresses and flexural strength criteria are met, a message will indicate that a satisfactory pattern has been found, and the pattern is displayed for review and final editing.

In most cases, the most efficient way to design a strand pattern is to use the auto pattern design option. Assuming that the data for the job was entered correctly and a reasonable strand template (description of where strands can be placed within the beam) was defined, then this is the quickest way to arrive at a feasible strand pattern. It may require fine-tuning, but it will likely indicate the least number of strands necessary for a satisfactory design.

Strand

This section allows users to define the basic properties of the strands used in the design.

• Top Strand Count: Specifies the number of strands to be placed at the top of the girder.

• Size: Defines the diameter of the strands (e.g., "0.6"").

• Material: Select the material type for the strands (e.g., "1/2" Default").

• Percent Pull: Indicates the percentage of the maximum allowable prestress applied to the strands (e.g., "75.0%").

Draping

This section enables users to configure draping methods and locations for the strands.

• Method: Allows you to select the draping technique for the strands. Options include:

  • None: No draping applied; strands remain in their default positions.

  • Pipe: Need more info.

  • Template Point: Strands are draped based on predefined template points.

  • Pinched Hold Down: Strands are draped and restrained at specific hold-down points.

• Relative Location:

  • Specifies the location where the draping method is applied, relative to the girder's geometry.