Modelling of connection between tunnel lining

RE: Modelling of connection between tunnel lining

Ze Yang Lee — Thu, 29 Apr 2021 06:14:19 GMT

The beam element connected with both ends released would act like a hinge, does not allow any force to be transferred.

RE: Modelling of connection between tunnel lining

Sye — Fri, 07 Aug 2020 22:38:18 GMT

If you release MY and MZ there will be no moment transfer but shear would still be transferred as long as you are not releasing FY and FZ.

RE: Modelling of connection between tunnel lining

Ze Yang Lee — Fri, 07 Aug 2020 02:15:49 GMT

Thanks for your reply Sye.

I have tried to release MY and MZ at the start and ends of those beams (connector) but it will turn them into a hinged connected members with no shear forces in them and is not helping to transfer any forces from the broken ring to the complete ring.

If I do not release them, there will be shear forces and bending moments and it seems like, only fix connection will work. Also, if the gap is bigger, (longer beam) you will see bigger bending moment and shear force in the beam.

In reality, the 'beams' are dowels connecting between ring to ring so there won't be physical gap between them, purely shear transfer interaction.

Do you have any suggestion sir.

Thanks a lot.

RE: Modelling of connection between tunnel lining

Sye — Wed, 05 Aug 2020 19:35:21 GMT

The way you have modeled with the gap and the small connecting beam is fine. Only thing is, you need to release MY MZ at the start and ends of these beams. Also you have defined spring stiffness KFY and KFZ. Since you have modeled the dowels as is, I would not define any additional springs as such and just analyze with the moment releases. That way you would get the shears in those members as you would get in your actual dowels which can then be checked against the allowable value.