Modelling Tunnel Lining
Modelling Tunnel Lining
(OP)
Hi guys,
I'm a graduate engineer and I'm looking at modelling a steel tunnel lining in Spacegass.
I have all of the information including the geotech report but I am having trouble inputting the support conditions. I know there should be springs (reflective of the soil spring stiffness) at the nodes on the circumference of the tunnel but I can only input these supports in either the X or Y directions and not RADIALLY, which would give a much more accuare refelctions. Any ideas of how one could solve this problem?
Any help from people with experience in this artea would be much appreciated!
http://s1.postimg.org/60oi6m30v/tunnel_liner.jpg
http://s3.postimg.org/vaqd0lkxv/tunnel_liner_2.jpg
I'm a graduate engineer and I'm looking at modelling a steel tunnel lining in Spacegass.
I have all of the information including the geotech report but I am having trouble inputting the support conditions. I know there should be springs (reflective of the soil spring stiffness) at the nodes on the circumference of the tunnel but I can only input these supports in either the X or Y directions and not RADIALLY, which would give a much more accuare refelctions. Any ideas of how one could solve this problem?
Any help from people with experience in this artea would be much appreciated!
http://s1.postimg.org/60oi6m30v/tunnel_liner.jpg
http://s3.postimg.org/vaqd0lkxv/tunnel_liner_2.jpg






RE: Modelling Tunnel Lining
The middle slice to have springs in both directions (each multiplied by 1/root2)?
Seems as though what you need is to manipulate each node's local axis, so it doesn't just refer to the global axis.
RE: Modelling Tunnel Lining
Thank you!
So you're saying I should just manipulate the axis of each node and then calculate the resultant stiffness using pytahgoras?
Regards,
Keith
RE: Modelling Tunnel Lining
My slicing up the quadrants idea is based on not being able to manipulate the node's axis - thus why it's an approximation for each slice.
And yeah the middle slice based on a assumed 45 deg angle.
RE: Modelling Tunnel Lining
RE: Modelling Tunnel Lining
RE: Modelling Tunnel Lining
RE: Modelling Tunnel Lining
RE: Modelling Tunnel Lining
What are you trying to accomplish with your analysis? What type of earth or rock are you trying to support? How are you modeling earth/rock pressures, as uniformly distributed?
Our problem was blocky rock that had large boulders coming loose from the tunneling process removing ambient rock pressure. The "goonies", what the miners called large falling rocks, couldn't be rock-bolted because of their immediate instability. We used stamped steel liner plates because we had them on hand. Everybody said we should be using cast steel or concrete liners due to the point loadings, but the Project Manager said, "Make the damned stamped plates work or you can all go to work for Kiewit!" (Kiewit paid low at the time. The liners did work and the Hudson River is now "clean".