How to decide when to check on "Initial Tangent Displacement for Erected Structures" in Construction Stage Analysis Control?

Creation date: 8/13/2018 7:23 AM    Updated: 5/19/2023 8:55 AM    camber construction stage analysis control tangent displacement


Answer:

Hi User,
Thanks for writing to us!

Generally, whether to consider tangent displacement or not depends on the construction process implemented on-site.
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Detailed Explanation of Deformation in midas Civil

Joint: where next segments of CS2 are added to the already activated segments of CS1.

Generally, in the analysis, when new segments are activated, the joints enter at the location that was initially given to them in the input data (at the original position), thereby creating the discontinuities at the joint locations.

1) One way to avoid these discontinuities is to rather apply the new segments tangentially than straight-forward.
2) Another way is to calculate the tangent displacement and add it to the CS-displacement. (This feature is implemented in midas civil to auto-calculate the tangent displacements).

We can have three possible deformation configurations in construction stage analysis. Usually, in our daily projects we match cast the segments, hence tangent displacements need to be considered.


In MIDAS/Civil using the option initial tangent displacement for erected structures for the construction stage analysis, the real displacement may be calculated for all members or for specific groups only. If this option is not chosen all segments will be applied straight-forward(standard cast- first sequence in the above figure) instead of tangentially and a discontinuity is introduced at the joints between the segments.

Conclusion:
1) Construction Camber  -  No tangent displacements included   - used for Segmental Cast-in-situ construction.
2) Manufacture Camber  -  Tangent displacements included        - used for fabrication cambers for structural steel and precast concrete members
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kindly go through this interesting video to understand the difference.
Link:

https://www.youtube.com/watch?v=-M_DfsDnKKI

Hope this clarifies!

Regards,

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