Hi all,
In tutorial 7 of plaxis 3D - Phased excavation of a shield tunnel, I wonder why the surface contraction is not applied on the surface of 1.5-m-long ring segments after the TBM because the section 5.5.6 surface contraction in Plaxis 3D reference manual mentioned that "If a contraction was already applied in the previous phase, assigning 0 to the value will implicitly apply a contraction with the same value but in the opposite direction resulting in a zero contraction at the end of the current phase". Therefore, not applying surface contraction on 1.5-m-long ring segments means the volume loss of these segments will return to 0, which is unrealistic. I am modeling tunnel excavation with a volume of 1%, so I wonder whether I should use a surface contract for ring segments after the TBM or just ignore it and follow the tutorial.
Thank you