NR NR/L2/CIV/086 ISSUE 12 PDF

This business process applies to all earthworks within the boundary of the Network Rail infrastructure (including approach embankments, approach cuttings, tunnel cuttings, slopes above tunnel portals, nailed or reinforced soil structures and any embankment, irrespective of its height, that also acts as a coastal, estuarine or river defence).

It also covers outside party slopes which might impact the infrastructure, and can be examined using the Soil Cutting Hazard Index (SCHI), Soil Embankment Hazard Index (SEHI) and the Rock Slope Hazard Index (RSHI).

NOTE 1: Approach embankments applies to overline bridges that are equal to or greater than 3 metres high, except those owned by a highway authority, roads authority or other competent authority.

NOTE 2: Reinforced soil structures applies to those whose face angle is less than or equal to 70 degrees to the horizontal.

This business process does not apply to:

a) examinations specifically carried out to assess ground movements resulting from mineral extraction, (refer to NR/L2/CIV/191);

b) the examination of vegetation (refer to NR/L2/OTK/5201);

c) the examination of drainage condition and structure (refer to NR/L3/CIV/005);

d) the examination of nailed or reinforced soil structures steeper than 70 degrees, retaining walls and gabion walls (refer to NR/L3/CIV/006);

e) the examination of coastal, estuarine or river defence works that are not also embankments (refer to NR/L3/CIV/006);

Purpose 

This document defines procedures and processes documented within the geotechnical control framework to manage earthwork assets. Earthwork management helps to control risks associated with the following loss events: 

a) Slope failure leading to loss of gauge capability; 

b) Slope failure leading to loss of track support and/or geometry; and 

c) Slope failure leading to loss of safe environment without loss of gauge capability or track support/geometry