tunnel

Question

is there someone here who modeled a tunnel by the NATM method using the embded beam.
personally in the part of the calculations when I take a length of more than 50 of tunnel the calculations stop. is there a reason ?? provide me with the characteristics of the embded beams (E, y, T ...) which represent the tunnel reinforcement umbrella vaults pleaase .

Stefanos Papavasileiou · Answer

Dear Roumaissa, 
 By a length of more than 50, I assume you mean in meters, but it is not clear in the description. I find it odd the calculation to depend on the length the tunnel extends so I would like to check the model, if you can share it: https://apps.bentley.com/srmanager/ProductSupport 
 Concerning the parameters for embedded beams, this is a part that we cannot comment on as it is on the geotechnical engineer to use the values provided from the manufacturer or by using the properties used in similar projects. Note that the embedded beams' parameters, which represent either rock nailing or an umbrella arch (or any other means of support), strongly depend on the soil or rock characteristics so it also not so easy to simply provide any values.