Bridge Tendon Data Form

Tendon assignments include the following tasks:

• Location of the start and end of the tendon

• The vertical and horizontal layout of the tendon

• Tendon section properties, loss parameters and jacking options

• The tendon load specified as either a force or a stress

• The tendon modeling option, which is either to model the tendon as loads or as elements

Several quick start options are available to assist in defining the tendon geometry. A parabolic calculator is provided in the layout of parabolic tendons.

Use the Bridge Tendon Data form to specify the various parameters needed to define prestressed tendons for the bridge model.

• Tendon Name edit box. Use the default or type in a new name for the tendon definition.

• Tendon Load Pattern drop-down list. Select the load pattern to which the prestress tendon definition should be added.

• Tendon Start Location and Tendon End Location

• • Span drop-down lists. Select the span(s) where the tendon will Start and End.

  • Start Location and End Location drop-down lists. Select to start the tendon at the beginning of the selected span or select User Definition to specify a location for the start of the tendon. Select to end the tendon at the end of the selected span or select User Definition to specify a location for the end of the tendon.

  • • Span Length display boxes. If Start of Span is selected in the Start Location Type drop-down list, the length of the specified span is shown in this display box. If End of Span is selected in the End Location Type drop-down list, the length of the specified span is shown in this display box.

    • Distance Along Span edit box. If User Definition is selected in the Start Location Type drop-down list, use this edit box to specify the distance from the left edge of the specified span to the location of the start of the tendon. If User Definition is selected in the End Location Type drop-down list, use this edit box to specify the distance from the left edge of the specified span to the location of the end of the tendon.

• Edit Vertical Layout button and the Edit Horizontal Layout button. Click these buttons to display the Tendon Vertical Layout Data form or the Tendon Horizontal Layout Data form with the options needed to specify the vertical and horizontal layout of the tendon.

Alternatively, use the Quick Start buttons to display the Tendon Quick Start form, which has a number of options for the vertical or horizontal tendon alignment. Select an option by clicking on it and then click the OK button.

• If a straight tendon option is chosen, the Bridge Tendon Data form will redisplay with the selected option transferred automatically to it. If additional changes are needed, click the Edit Vertical Layout button or the Edit Horizontal Layout button to display the Tendon Vertical Layout Data form or the Tendon Horizontal Layout Data form, which will be loaded with the selected template layout.

• If a parabolic tendon option is chosen, the  Define Parabolic Tendon {Horizontal, Vertical} Layout By Points form will display. Use that form to refine the layout. Click the Done button on that form to transfer the refined layout to the Tendon Data  form.

• Tendon Parameters

• • Prestress Type drop-down list. At the present time, Post Tension is the only available option.

  • Jack From drop-down list. Use this drop-down list to specify the location for jacking the tendon: the Start, the End, or Both the start and the end of the tendon.

  • Material Property drop-down list. At the present time, Steel is the only available option.

  • Tendon Area edit box. Use this edit box to specify the area of the tendon in length2.

  • Max Discretization Length edit box. Use the defaults or specify the maximum prestress tendon discretization length in this edit box.

  • Design Params. button. Click this button to access the Tendon Design Parameters form. Use the form to specify the design parameters for the tendon.

  • Loss Params button. Click this button to display the Prestress Loss Parameters form and specify friction and anchorage losses, and in the case of tendons being modeled as loads, elastic shortening stress, creep stress, shrinkage stress and steel relaxation stress.

• Load Type options and Tendon Load edit box. Choose to apply the load as a Force or a Stress and then enter a value in the Tendon Load Force/Stress edit box.

• Tendon Modeling Options. Choose the option to be used in the analysis model for the prestress:

• • Model as Loads option. When this option is selected, values can be specified for Elastic Shortening Stress, Creep Stress, Shrinkage Stress, and Steel Relaxation Stress on the Prestress Loss Parameters form (see above).

  • Model as Elements option. When this option is selected, the program can consider the losses for Elastic Shortening Stress, Creep Stress, Shrinkage Stress, and Steel Relaxation Stress automatically and accurately in the analysis if the appropriate material property has been specified and the appropriate load case options are used.

• Units drop-down list. Use the displayed units or select new units from the drop-down list.

• Move Tendon button. Click this button to display the Move Prestress Tendon form and move the defined tendon by a specified distance or to specified coordinates.

• Show Tabular Data button. Click this button to display the Tabulated Tendon Profile form.

• Tendon Layout Display area. Use the horizontal scroll bar at the bottom of the display area to drag the mouse pointer/red dot along the Reference Line or Tendon, depending on the selection made in the Snap To This Item area of the form. Double click on the view in this area of the form to display the Tendon Layout Display form and review the Elevation, Plan, and Section views of the model at the same time.

• • Tendon Layout Display Options

  • • Show Elevation option. When this option is selected, an elevation view of the specified span is shown in the Tendon Layout Display area of the form.

    • Show Plan option. When this option is selected, a plan view of the specified span is shown in the Tendon Layout Display area of the form.

    • Show Section option. When this option is selected, a section view of the specified span is shown in the Tendon Layout Display area of the form.

  • Snap To This Item. Use the snap features to control the display of data for the mouse pointer location as the mouse is moved over the Elevation, Plan, or Section view.

  • • None option. When this option is chosen, no snaps are enabled and, as the mouse pointer is moved over any of the displays, the location of the mouse pointer will display, as appropriate, in the S, Z, X, Y, and X' and Y' display boxes in the Mouse Pointer Location area in the lower left of the form.

    • Reference Line option. When this option is chosen, CSiBridge displays a small red dot that snaps to the reference line and displays the coordinate data for that point along the reference line in the Mouse Pointer Location area in the lower left of the form.

    • Tendon option. When this option is chosen, CSiBridge displays a small red dot that snaps to the tendon and displays the coordinate data for that point along the tendon in the Mouse Pointer Location area in the lower left of the form.

  • Snap To This Span Location. Use these options in conjunction with the Reference Line and Tendon options.

  • • Anywhere Along Span option. When this option is chosen, CSiBridge snaps a small red dot to any location along the Reference Line or Tendon.

    • Every 1/___ of Span option. When this option is chosen, also specify the denominator of the fraction to specify a portion of the span. CSi Bridge snaps the small red dot to the Reference Line or Tendon in the specified fractional portion of the specified span.

  • Coordinate System drop-down list. Use the drop-down list to select a coordinate system other than global if one has been defined (see Define Coordinate Systems/Grids for more information about defining a coordinate system).

See Also

Bridge Wizard