NR NR/L2/CIV/169 ISSUE 2 PDF

Ownership and management 

This standard defines the requirements for new Tunnels and refurbishment works within existing Tunnels and is intended for use by all those involved with the design process. 

This standard applies to all new and existing rail tunnels owned or managed (solely or shared) by Network Rail (NR). 

This standard can also be applied to Tunnels that are designed and built by others, and that impact on existing NR infrastructure. 

Types of tunnel 

This standard is applicable to the design of permanent Tunnels (new or refurbished) and covers the design of: 

a) Bored lined tunnel - Brick & Masonry; 

b) Bored lined tunnel - Concrete Segmental; 

c) Bored lined tunnel - Sprayed Concrete Lining (SCL); 

d) Bored lined tunnel - Concrete Cast In-Situ; 

e) Bored lined tunnel – Metallic Segmental; 

f) Cut and Cover tunnel – Arched; 

g) Cut and Cover tunnel - Jack Arch; 

h) Jacked Box; 

i) Cut and Cover tunnel - Flat Soffit; 

j) Shafts (open, blind and hidden); 

k) Portals; 

l) Headwalls and shaft headwalls; 

m) Tunnel drainage including manifold installed as part of the lining design to convey groundwater to the tunnel carrier or cross drain. 

This standard is not applicable to the design of: 

a) Equipment support structures such as gantries for signals or overhead line electrification (OLE); 

b) Track drainage including carrier drains and cross drains beneath the track; 

c) Track alignment and trackwork; 

d) Mechanical and electrical equipment; 

e) Rock reinforcement for unlined Tunnels. 

Categories of work 

This standard applies to the design of: 

a) New Tunnels; 

b) Refurbished Tunnels; 

  • Repair works (e.g. like for like replacement); 

  • Alterations (e.g. increase gauge, change profile); 

  • Strengthening works (e.g. to increase load capacity); 

c) Monitoring of Tunnels during construction; 

d) Temporary works provided for the execution of the Tunnels. 

This standard applies to: 

e) All stages where permanent works and temporary works are taken into operational use refer to: Asset Management Plan, NR/L3/MTC/089.

Purpose 

The purpose of this standard is to define the requirements for the Design and enable the project team to confirm that the Design complies with all relevant codes and standards such that there is no unacceptable risk to safety as a result of the Design.