- Tendon elongations are produced in a spreadsheet format table.
One of the most essential preparations for stressing inspection is the calculation of theoretical elongations due to jacking. In addition to the use of a load cell to check prestress force, the tendon elongations must be measured and compared with the calculated theoretical elongations during the stressing operation.
The total elongation which the tendon has to achieve during stressing should be calculated as:
Δl_tot = Δl_p + Δl_c + Δl_sl + Δl_e
Δl_p: elongation of the tendon
Δl_c: elastic deformation of the concrete (shortening must be treated as a positive value)
Δl_sl: sum of anchor plates impressions and dead end wedge slip according anchorage type applied
Δl_e: elongation of the prestressing steel in the jack and seating device (if applicable)
The program shows Δl_p and Δl_c in the tendon elongation and the element elongation respectively.
If Tendon Profile is defined as 'Element Type'. the length of tendon is calculated based on referencing element's. Therefore, for tendons with radical curvature, the elongation calculation may not be accurate. In this case, it is recommended to define Tendon Profile as 'Straight' or 'Curve'.
- Table Tool in midas Civil offers a variety of powerful built-in functions. Refer to Usage of Table Tool for detail directions:
From the main menu, select [Results] tab > [Type : Analysis result] > [Table] group > [Results Tables] > [Tendon] > [Tendon Elongation]
Refer to Usage of Table Tool and check the following data:
Tendon Name : Tendon Name
Refer to Tendon Profile for the tendon names automatically assigned when the Bridge Wizard is used to model the structure.
Stage : Construction stage of prestressing the tendon
Step : Construction step of prestressing the tendon
Begin : Tendon Elongation at the start of the tendon
End : Tendon Elongation at the end of the tendon
Begin : Element Elongation at the start of the tendon
End : Element Elongation at the end of the tendon
Begin : Sum of the elongations of the tendon and element at the start of the tendon
End : Sum of the elongations of the tendon and element at the end of the tendon