Register now or log in to join your professional community.
Sorry, I am not into building tunnels and can not give you an answer on this subject,
however having worked in the railroad industry... I believe ISO has some regulations on the railroad industry
en.wikipedia.org/wiki/Railroad_tunnel
www.fhwa.dot.gov/bridge/tunnel/qa.cfm ... such as for compressed air tunnel ... information about the air capacity that is need in basic design of ventilation for railroad tunnels in rural area.
