Type 1
Define the type of PSC (prestressed and post-tensioned concrete) box, and define the properties, locations, arrangement type and stressing method of the top and bottom tendons (First phase tendons), which are stressed during the launching stages.
Top & Bottom Tendon dialog box (Type 1)
Type
None
No tendons are used.
One Cell
No interior web is present.
Two Cell
A single interior web partitions the PSC box.
Tendon Property
Select the tendon type.
Top
Tendons in top flange
Bottom
Tendons in bottom flange
Click the
button to the right of the selection field to prompt the "Tendoon Property" dialog box to add, check or modify the tendon properties.
Tendon Arrangement
Arrangement Type
Define the method of stressing the tendons.
2 Cycle : In the plan view, a group of every second tendons (alternating 50% of the total tendons) is stressed at a stage. The first group of 50% of the total tendons is stressed in the first segment on an alternating basis initially. The second group of the remaining 50% of the total tendons is stressed over the first and second segments. Each group of the tendons is stressed on an alternating basis at each stage over two segments for the subsequent stages except at the last segment. The last stage retains the reverse of the first stage.
3 Cycle : In the plan view, a group of every third tendons (one third of the total tendons) is stressed at a stage. The first group of one third of the total tendons is stressed in the first segment on the every-third-tendon basis initially. The second group of one third of the total tendons is stressed over the first and second segments. The third group of the remaining one third of the total tendons is stressed over the first, second and third segments. Each group of the tendons is stressed on the every-third-tendon basis at each stage over three segments for the subsequent stages except at the two last segments. The last two stages retain the reverse of the first two stages.
Tendon A Jacking Order
From the diagram in the dialog box, select the tensioning order for the tendon group containing the outer-most top tendon (Tendon A) depicted in green. The tensioning order may be first or second for the 2 cycle and first, second or third for the 3 cycle.
Tendon B Jacking Order
From the diagram in the dialog box, select the tensioning order for the tendon group containing the outer-most bottom tendon (Tendon B) depicted in green. The tensioning order may be first or second for the 2 cycle and first, second or third for the 3 cycle.
Jacking Stress
Specify the tensioning stresses for the top and bottom tendons.
Su
Ultimate tensile strength of tendons
Sy
Yield strength of tendons
Grouting
Once the ducts are grouted, the transformed section properties are subsequently considered. The input signifies the timing of incorporating the transformed properties.
Prestressing step
Grouting takes place at the time of tensioning the tendons.
Every n Stage
Grouting takes place at every n stages. If n=1is entered, the grouting is assumed to take place at the next stage after the corresponding tendons are stressed. If n=2 is entered, the grouting is assumed to take place at the third stage after the two corresponding segments have been stressed.
B1, B2, B3, ...
Referring to the guide diagram, input the number of tendons and dimensions to define the tendon placement.
Enter '0' for B3 and B5 if an odd number of tendons is placed. In the case of an even number of tendons, enter one half of the tendon spacing.
Tendon placement may be defined by the "Tendon Profile" function.
Type 2
Define the type of PSC (prestressed and post-tensioned concrete) box, and define the properties, locations, arrangement type and stressing method of the top and bottom tendons (First phase tendons), which are stressed during the launching stages.
Top & Bottom Tendon dialog box (Type 2)
Tendon Arrangement
Arrangement Type
Define the method of stressing the tendons.
2 Cycle : A group of every second tendons (alternating 50% of the total tendons) is stressed at a stage.
3 Cycle : A group of every third tendons (one third of the total tendons) is stressed at a stage.
Tendon A Jacking Order
From the diagram in the dialog box, select the tensioning order for the tendon group containing the outer-most top tendon (Tendon A) depicted in green. The tensioning order may be first or second for the 2 Cycle and first, second or third for the 3 Cycle.
Tendon B Jacking Order
From the diagram in the dialog box, select the tensioning order for the tendon group containing the outer-most bottom tendon (Tendon B) depicted in green. The tensioning order may be first or second for the 2 Cycle and first, second or third for the 3 Cycle.
Jacking Stress
Specify the tensioning stresses for the top and bottom tendons.
Su
Ultimate tensile strength of tendons
Sy
Yield strength of tendons
Grouting
Once the ducts are grouted, the transformed section properties of tendon and grout are subsequently considered. The input signifies the timing of incorporating the transformed properties.
From Construction Stage Analysis Control, specify whether to apply gross section or net section/transformed section for calculating section properties.
Prestressing step
Grouting takes place at the time of tensioning the tendons.
Every n Stage
Grouting takes place at every n stages. If n=1is entered, the grouting is assumed to take place at the next stage after the corresponding tendons are stressed. If n=2 is entered, the grouting is assumed to take place at the third stage after the two corresponding segments have been stressed.
Define Tendon Property
If Tendon Property has not been defined, click this button to define the Tendon Property.
Number of Cell
Number of Cells of PSC Box Section defined in Section tab.
Symmetric
Select this option when the web tendons at each side are symmetrical.
Ht
Vertical distance from the top edge of the section to the top tendon.
Hb
Vertical distance from the top end of the section to the bottom tendon.
Position
Select either Top or Bottom.
Baseline(m)
Enter the Baseline position, which will become a reference to simplify horizontal tendon placement.
Bli(m)
Among the tendons located at the left part of the web, enter the horizontal distance between the Baseline and the tendon, which is closest to the Baseline. Input a positive value regardless of the direction.
Nli
Enter the number of tendons located at the left part of the web.
Bri(m)
Among the tendons located at the right part of the web, enter the horizontal distance between the Baseline and the tendon, which is closest to the Baseline. Input a positive value regardless of the direction.
Nri
Enter the number of tendons located at the right part of the web.
ai
Enter the tendon spacing.
Tendon Property
Select the Tendon Property Type.