NR NR/L2/CIV/086/MOD02 ISSUE 2 PDF

The procedure set out in this document applies to all Network Rail owned or managed earthworks. This includes natural slopes inventoried and inspected as if they are earthworks. For geohazard assessment of Outside Party slopes, see NR/L2/CIV/086/mod03.

The procedure offers a tiered framework for earthwork assessment. The framework comprises four levels (0 to 3) of assessment of increasing sophistication, and therefore cost, but consequently reducing application. Level 0 assessment is applied to all earthworks. Level 1 to 3 assessment is applied at the discretion of an evaluator. The scope of an individual level 1 to 3 assessment is as determined during earthwork evaluation (and for assessment levels 2 and 3 recorded in the assessment remit).

This document does not cover:

a) Operational or occupational health and safety requirements related to carrying out earthwork assessments, see NR/L2/OHS/019 or NR/L3/OHS/005 as applicable;

b) Guidance for how to undertake ground investigation in support of earthwork assessment, see NR/L2/CIV/071 Design of Geotechnical Structures; and

c) Guidance for how to undertake extended monitoring beyond ground investigation in support of earthwork assessment, see NR/L2/CIV/086/mod06. 

Purpose 

This document defines the procedure for carrying out earthwork assessment. Earthwork assessment is the qualitative or quantitative determination of the stability or the safe load-carrying capacity of an earthwork. 

Earthwork assessment helps control risks associated with the following loss events: 

a) Earthwork or slope failure leading to loss of gauge capability; 

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

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

Earthwork assessment works in harmony with earthwork evaluation (see NR/L2/CIV/086/mod01). The outcome of an assessment provides an essential input to an earthwork evaluation whilst the requirement for further assessment is determined during earthwork evaluation.