Define pre/post-tensioned tendons.
For the precast girder type, tendons defined for each span are considered to be the pre-tensioned tendon only. Pre-tensioned tendons are automatically activated when the girder per span is activated during the construction stages.
For the splice girder type, both pre-tensioned tendons and post-tensioned tendons can be defined. The pre-tensioned tendons are defined for the segments divided at the splice locations; the post-tensioned tendons can be defined for all spans along the bridge.
Pre-tensioned tendons are automatically activated when the girder segments are activated during the construction stages.
Post-tensioned tendons are activated before/after deck cast during the construction stages. Post-tensioning can be distinguished for the 1st post-tensioning and 2nd post-tensioning.
From the main menu, select [Structure] tab > [PSC Bridge] group > [Prestressed Composite Bridge]
Fig. Prestressed Composite Bridge Wizard Tendon dialog box
Tendon Assignment Table
Tendon details are defined for each layer of tendons. Same-height tendons can be considered as the same layer and each layer can defined together with the same table row. Each table row is defined as tendon type, tendon property, number of tendons, transverse distance, etc...
Tendon Assignment Name : Select the specific tendon name
Tendon property : Define the tendon properties. Click to define new, modify, or delete previously defined tendon properties.
Segments : It represents a unit segment that can be defined as the tendon profile.
For precast girder type, it is shown as each span. E.g. for the 3 spans continuous precast girder, “Segment” is shown as Span1, Span2, and Span3, and each span can be defined as the pre-tensioned tendon profile.
For the splice girder type, the segment girder that is separated by splice is shown as each Segment 1, Segment 2, Etc.
It is used to define the pre-tensioned tendon. Segment “All” which includes the entire girder is used to define the post-tensioned tendon. E.g. for 2 spans splice girder with 2 splice positions, “Segments” is divided into 3 segments and All (that is “Segment 1”, ”Segment 2”, ”Segment 3”, and “All”.
Section Reference Line : Specify the reference line to define the tendon layout. After selecting the section reference line, each tendon information can be input according to the reference line.
Fig. Section reference line
Center : The reference line is set based on the centroid of the section.
Left/Right : The reference line is set based on the Left/Right end of the section.
Fig. Patterns of tendons
Section (End A-A) represents the end section of the segment start. The elevation view is represented by segment grouping. Zoom in, and out and moving the drawing is possible with the placing mouse in the drawing.
Type : Specify the type of pattern for the tendon, such as straight, harped1, 2, and curved. Each type has a minimum required dimension (D, H1~H5, L1, and L2) that specifies the tendon profile.
Tendon property : Specify the tendon properties
Number of Tendons : Input the number of tendons in each layer.
Specify the distance dimensions related to the transverse tendon gap in the same layer profile
The distance can be possible input equal and unequal spacing and type in the form of “@” or “,”. For equal distance, type in the form of “number of distance@distance”.
In the case of selecting the “Center” section reference line, the placement of the total tendon of each layer is located in the middle of the transverse width. In the case of selecting the “Left”/”Right” section reference line, the tendon is arranged in the transverse spacing from distance “D”.
D: Distance from the left and right section reference line. The left (right) end side of a cross-section is a section reference line when “Left” (“Right”) is selected in the section reference line. It is deactivated when “Center” is selected in the section reference line.
Fig. Definition of symbols depending on tendon types
H1 : A vertical distance from the top of a section in a start-end position.
H2 : A vertical distance from the bottom of a section in the middle of the 1st span position.
H3 : A vertical distance from the top of a section in the 1st support position.
H4 : A vertical distance from the bottom of a section in the middle of 2nd span position.
H5 : A vertical distance from the top of a section in the 2nd support position.
L1 : A longitudinal distance from 1st span start position.
L2 : A longitudinal distance from 2nd span start position.
The tendon is placed with symmetric conditions in default.
Specify the pre/post-tensioning stress
Grouting: after n stage
Define the stage at which the tendons are grouted in the ducts (sheathes). The grouting stage determines the timing of using the transformed section with the grouted tendons. Once the ducts are grouted, the transformed section properties are subsequently considered. The input signifies the timing of incorporating the transformed properties.
Detailed : Specify and modify the jacking stress and debonding tendon length of each tendon in detail. The entries in the “Name” column (T1, T2,…Tn) represent horizontal tendon layers starting from the lowermost tendon layer in the section. The entries in the “No.” column identify individual tendons in a particular layer starting from the left-most tendon.
Fig. Detailed Tendon dialog
The entries in the “Name” column (T1,T2,…Tn) represent horizontal tendon layers starting from the lowermost tendon layer in the section
The entries in the “No.” column identify individual tendons in a particular layer starting from the left-most tendon.
Tendon Assignment List
After finishing the tendon definition of each table row in the tendon assignment table, click “Add” to save each tendon assignment of segments.
Name : Tendon assignment names are saved
Total Strand : Summation of the total number of tendons in the segment. It is obtained by adding up the total number of tendons used in each row in the same tendon assignment name section.
Add : Click to enter new or additional tendon placement in the tendon assignment table.
Modify : Select the tendon assignment list to be modified, then the upper tendon assignment table data is displayed and can be modified the data. Click Modify to modify the upper tendon assignment table data.
Delete : Select the tendon assignment list to be deleted and click Delete to eliminate a previously defined tendon assignment table data.