Hello everyone,
I am modelling an existing multi-span prestressed concrete bridge (Talbrücke), originally constructed span by span using a movable scaffolding system (Vorschubrüstung).
In CSM, I activate the stiffness of each new construction segment first (ICS1) and its self-weight later (ICSD), using CTRL CANT 0.
My problem is that noticeable geometric kinks appear at the construction joints when the next segment is activated.
According to the original construction documentation, the fresh concrete load is initially transferred to the cantilever of the preceding segment. After the new concrete hardens, the Vorschubrüstung is lowered, the temporary load is removed, and the new segment’s self-weight becomes active.
I also tested this sequence in a simplified three-span model. The temporary load is correctly removed, but its influence on the deformation is not completely reversed after the next segment’s stiffness has been activated.
Interestingly, when I use tangential erection (CTRL CANT 2), the kinks disappear, but the bridge progressively deflects upward as new segments are activated.
My questions are:
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What is the recommended CSM approach for modelling this construction method?
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Is
CAMB MODE LINEthe appropriate solution for the geometric kinks, or should the segment activation/erection method be modified? -
Are there any SOFiSTiK examples specifically dealing with bridges constructed using a Vorschubrüstung?
Any advice or references to relevant examples would be greatly appreciated.
Thank you!