I have a prestressed bridge with an important torsional component due to its curved geometry. I have set only one reinforcement layer with torsional contribution and with 4 rebars in SOFIPLUS.
When I use the CSM Bridge Design module, the created .dat file uses an AQB run where CTRL VM VAL2 1.0 is set. In the AQB Documentation we read that this command essentially makes the program consider the shift rule (Versatzmass) for the calculation of the longitudinal reinforcement due to the torsional load.
What I see in the results is that the layer with the torsional contribution remains unchanged which I find quite surprising. Furthermore when I change the CTRL VM VAL2 to 0 the same torsional layer augments substantially reaching very high quantities along the bridge while the stirrups become less.
Now I fail to understand how the consideration or not of the shift rule for the longitudinal reinforcement can have such a big impact on the one torsional layer and on the stirrups. Could somebody help me understand the inner workings of this command and which one of the VAL2 values I should use (0 or 1)? Unfortunately the AQB documentation is not very helpful in this aspect.