Precast/Prestressed Girder Help

Start of Tutorial

For Tutorial 3, instead of inputting most of the data manually, you will load an existing file (Tutorial 3). Select Open from the File menu and select “Tutor3.csl” from the list and click Open. A warning message will appear saying “The following beam section could not be found in the library: B36-60 (Span: 1, Beam: 1).” Click Yes to add the beam section to the library and continue to the Project tab.

Before proceeding with the design, follow steps 1-8, which illustrate how to access the libraries and/or make modifications.

  1. Precast/Prestressed Girder allows modifications to the library. As explained, you have just added the “B36-60 Spread Box Beam” to the Beam Section library. To verify that it has been added, sthat you can also add, delete, modify, or copy a beam section in this screen. Select Beam Sections from the Libraries menu. The Beam Sections Library will display, as shown in Figure T13-5.
    Note: you can also add, delete, modify, or copy a beam section in this screen.

    Figure 1 Beam Sections Library

    Note: Precast/Prestressed Girder comes with standard default libraries, the contents of which are discussed in Appendix C. Verifythe section property and dimension information, as shown in Figure 2.
  2. Select Spread Box Beam under Type, highlight B36-60 beam in the list, and click Modify. The Spread Box Beam Section displays, as shown in Figure 2. This screen contains the beam ID and description, dimensions, and section properties for the B36-60 spread box beam.

    Figure 2 Spread Box Beam Section

  3. To illustrate the different section property options, select the Dimensions option undSection Propertieser Section Properties. The program will automatically calculate the center of gravity, area, moment of inertia, and volume/area based on the section dimensions.
    Note: the Cg, Area, MI, and Vol/Area are computed automatically (e.g.A = 882 in2) and the values are grayedout. Select the User Input option under Section Properties to return to the original beam section properties.
  4. Click Template to activate the Template, as shown in Figure 3. The End Template contains the locations where the strands may be located at the end of the beam.

    Figure 4 Template

    Add, delete, or modify the template locations by selecting the desired template row in the list. Note that the red line in the section view indicates the corresponding template row location. Make the appropriate changes to the number of strands and height, then select either Add, Delete, or Modify. Click Cancel and return to the Spread Box Beam Section.

  5. From the Spread Beam Box Section window, select Edit. The Section Drawing Editor will open, as shown in Figure 4.

    Figure 4 Section Drawing

    1. The section drawing editor computes the beam section properties based on the x and y vertex coordinates. The vertex coordinates can be changed by clicking Show Vertex and inputting new values for the x and y coordinates, or graphically by clicking either Add Node, Delete Node, or Modify Node.
    2. Modify the grid spacing, snap, and limit controls by clicking Drawing Properties Settings to activate the Drawing Properties.
    3. To accept the section drawing properties and return to the Spread Box Beam Section, click the yellow check mark button. The program will update the section properties. Note, the section drawing editor is used only for computing section properties, all engineering calculations are based upon the individual beam dimensions entered in the Beam Section.
    4. To close the Section Drawing screen, click the X in the top right corner of the screen and return to the Spread Box Beam Section. To continue, make sure the User Input option is selected under Section Properties and click Cancel.
  6. If any changes have been made to the library, a dialog box will appear asking for the file name where you want to save the modified beam section library. Generally, you will accept the default library (default.cs1) unless you want to have more than one library. To update the current library (i.e., default. cs1) click Save. A warning message appears stating that the section properties have changed. Select Yes to update with the new/current properties, or select No to use existing section properties. Click Close to return to the Project .
  7. Select Prestressing Tendon from the Libraries menu (or its respective icon). The Prestressing Tendon Library will display, as shown in Figure 5. This option allows you to modify the strand library.

    Figure 5 Prestressing Tendon Library

    Data entry is similar to the Beam Sections Library. For this tutorial, you will not modify the strand library. Click Close without making any changes and return to the program.

  8. Select Live Load from the Libraries menu (or its respective icon) to activate the Live Load Library, as shown in Figure 6. This option allows you to add, delete, modify, or copy the live load library.

    Data entry is similar to the Beam Sections and Prestressing Tendon Library. For this tutorial, you will not modify the live load library. Click Close without making any changes and return to the program.

Parent topic: Continuous 2-Span Prestressed Spread Box Beam Design (U.S. Units) (LFD)