scope:

This document is to provide guidance on the application of the requirements for the Bridge Structure assets owned by LU through the life cycle stages:

a) Inception and design

b) Construction, installation, testing and commissioning

c) Inspection

d) Analytical assessment

e) Condition assessment and certification

f) Maintenance

g) Strengthening and renewal

h) Decommissioning.

This Guidance Document mirrors the sub-section headings of LU standard S1051 'Civil Engineering - Bridge Structures' at the start of each life cycle section, but additionally has further sub-sections added to each life-cycle section where there is further guidance material available to LU that does not specifically relate to the sub-section headings used in the standard, or is better set out separately.

The information contained in this guidance is derived mainly from historical information contained in existing LU documents and therefore does not necessarily reflect current good practice. Where possible, existing historical information has been supplemented by references to current good industry practice.

This document is applicable to designers of new Bridge Structure assets as well as maintainers and assessors of LU Bridge Structures assets as defined in section 1.

Purpose

The purpose of this guidance is to support London Underground (LU) standard S1051 'Civil Engineering - Bridge Structures' and provides guidance on established good practice solutions that meet the requirements of that standard.

The Bridge Structure assets comprise:

a) Rail bridges. This category of structure covers structures owned by LU carrying LU tracks, including:

I) Underbridge

II) Overbridge

III) Viaduct

IV) Girdering

V) Way beams.

b) Highway bridges.

This category of structure covers structures owned by LU carrying public or private road traffic, including:

I) Overbridge

II) Viaduct.

c) Footbridges

d) Underground structures.

This category of structure covers:

I) Covered ways

II) Subsurface tunnels (i.e. cut and cover tunnel)

III) Subways

IV) Culverts.

e) Earth retaining walls, including gabions

f) Ancillary structures and components. This category of structure covers:

I) Cable bridges

II) Pipe bridges

III) Pipe crossings over / under track

IV) Signal gantries

V) Gantries over railway

VI) Crash barriers

VII) Longitudinal timbers.