Hello, while checking the models by our Design consultant of the tunnel, I am unable to locate grouting loads in it. He has provided a separate analysis in STAAD model for it. The same has been done in other projects also. Can you tell me how to define those loads?
Dear Hesoyam,
You will have to give some more information, like what kind of tunnel (TBM, shield, NATM....) and what "grouting loads" you refer to. That can be shotcrete, injection, tail void, bore front stabilization grouting...?
With kind regards,
Dennis Waterman
Hello Sir,
I am currently checking design of TBM tunnel and for grouting i mean tail void grouting loads. I cant locate them in model submiited by our consultant. Or can you suggest me if there an option to add that load on the lining. (sorry english is not my primary language)
Tail void grouting influences both the lining loads and deformations as well as the ground surface settlements, so just applying a load on the lining may not be enough.
For instance Tutorial 4 of the PLAXIS 2D 2023 Tutorial manual gives in detail how to model tail void grouting using the so-called grout pressure method.There are other methods like modelling a ring around the tunnel in which either a user-defined pore pressure pressure or a volume strain is applied. These methods are a more accurate way of modelling tail void pressure, especially with respect to structural forces, but it generally requires to uncouple the TBM modelling and lining modelling by for instance using a plate element for the TBM and volume elements for the lining. Hence, it would require a significant change to your model.One way or the other, you would have to modify your model and probably redefine the calculation phases in order to introduce the tail void grouting if this was forgotten in the original model.