Shape of tunnel

[taepn]

hello everyone,
could you recommend the suitable shape of the railway tunnel to allow the train on double track dive under another train on above ground?

 

[PaxVobiscum]

Please reassure us you are not a Civil Engineer with Network Rail.

 

[taepn]

Please reassure us you are not a Civil Engineer with Network Rail.

Sure, I am a student and now studying on tunnel construction but no experience in this field.

 

[furnessvale]

hello everyone,
could you recommend the suitable shape of the railway tunnel to allow the train on double track dive under another train on above ground?

The way you describe things tells me that the overall construction depth of the lines diving under needs to be kept to a minimum.

If that is the case, my initial thought would be to consider twin single bores for the dive under which should deliver a reduced construction depth compared to a double tracked bore. Either option would normally be circular cross section, possibly concrete segments/

Alternatively, you could consider cut and cover, building what is effectively a bridge over the diving lines. This bridge could be beams on concrete abutments which would deliver the smallest construction depth.

 

[Tio Terry]

hello everyone,
could you recommend the suitable shape of the railway tunnel to allow the train on double track dive under another train on above ground?

I think you would benefit from reading the Technical Specifications for Interoperability, in particular those applicable to Safety in Railway Tunnels, Energy and Persons of reduced mobility. All of those have some influence on the design of a tunnel.

 

[najaB]

Alternatively, you could consider cut and cover, building what is effectively a bridge over the diving lines. This bridge could be beams on concrete abutments which would deliver the smallest construction depth.

Suggestion seconded. All things being equal it's easier to build over a railway than under it.

 

[Joseph_Locke]

It depends also on how you build the tunnel underneath, what the ground is like you are tunneling through and if you want to keep the railway above open or not ..

 

[furnessvale]

It depends also on how you build the tunnel underneath, what the ground is like you are tunneling through and if you want to keep the railway above open or not ..

Indeed, the original question is in the "how long is a piece of string" category.