Safe Asset Management - Embankments and Cuttings

Transcription

1 Safe Asset Management - Embankments and Cuttings Synopsis This document sets out requirements for the safe management of embankments, cuttings and natural slopes. Submitted by Martin Fargher Standards Project Manager Authorised by Brian Alston Controller, s This document is the property of Railtrack PLC. It shall not be reproduced in whole or in part without the written permission of the Controller, s, Railtrack PLC. Published by Safety & Standards Directorate Railtrack PLC Railtrack House DP01 Euston Square London NW1 2EE Copyright 1999 Railtrack PLC

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3 Page 1 of 7 Contents Section Description Page Part A Issue Record 2 Responsibilities 2 Compliance 2 Health and Safety Responsibilities 2 Supply 2 Part B 1 Purpose 3 2 Scope 3 3 Definitions 3 4 Principles 3 5 Competency 4 6 Requirements 4 7 Neighbouring Earthworks 6 8 Inspections of Track Support 6 9 Records 6 References 7 RAILTRACK 1

4 Page 2 of 7 Withdrawn Document Issue Record Part A This document will be updated when necessary by distribution of a complete replacement. Amended or additional parts of revised pages have not been marked by a vertical black line in the adjacent margin because the document has been revised throughout. Issue Date Comments One January 1996 Original Document Two December 1999 Supersedes Issue 1, revised throughout Responsibilities s are mandatory on all members of the Railway Group * and apply to all relevant activities that fall into the scope of each individual s Railway Safety Case. If any of those activities are performed by a contractor, the contractor s obligation in respect of s is determined by the terms of the contract between the respective parties. Where a contractor is a duty holder of a Railway Safety Case then s apply directly to the activities described in the Safety Case. * The Railway Group comprises Railtrack and the duty holders of the Railway Safety Cases accepted by Railtrack. Compliance Except for the inclusion of retaining walls less than 3m high and natural slopes on a register, the compliance date is 1 April For the inclusion of retaining walls less than 3m high and natural slopes on a register, the compliance date is 6 April Health and Safety Responsibilities In issuing this document, Railtrack PLC makes no warranties, express or implied, that compliance with all or any documents published by the Safety & Standards Directorate is sufficient on its own to ensure safe systems of work or operation. Each user is reminded of its own responsibilities to ensure health and safety at work and its individual duties under health and safety legislation. Supply Controlled and uncontrolled copies of this document may be obtained from the Industry Safety Liaison Dept, Safety and Standards Directorate, Railtrack PLC, Railtrack House, DP01, Euston Square, London, NW1 2EE. 2 RAILTRACK

5 Page 3 of 7 1 Purpose 2 Scope Part B The purpose of this document is to set out the requirements for the safe management of embankments, cuttings and natural slopes. The contents of this document apply to all embankments and cuttings forming railway infrastructure identified in GA/RT6001 as being applicable to Railway Group Standards including cuttings adjacent to tunnel portals and natural slopes whose failure could affect the safety of train operations. In the case of natural slopes it only applies to those locations where there is a known history of instability that could affect the safety of train operations. This document also applies to those embankments and cuttings owned or controlled by an outside party where instability or slope failure could affect the safety of train operations (see section 7). The document does not apply to the approaches of road over rail bridges except where failure of the approach may introduce a risk to the safety of train operations. The requirements of this document apply to all persons within the Railway Group responsible for the examination, evaluation of the condition or maintenance of embankments, cuttings or natural slopes. 3 Definitions Cutting An excavation that allows railway lines or access roads to pass through surrounding ground at an acceptable level and gradient. Embankment An earthwork that allows railway lines or access roads to pass over low lying ground, or ground liable to flood, at an acceptable level and gradient. Natural Slope Sloping ground that has been formed by natural processes. Rock Cutting A cutting where the dominant mode of slope failure is along a discontinuity within the rock mass. Slope Failure Any rock fall or soil slip, slide, or flow in a cutting or natural slope, or soil slide or slip in an embankment or natural slope. 4 Principles This document supports Principle 8 contained in HMRI Railway Safety Principles and Guidance Earthworks and structures above or adjacent to the railway should be capable of supporting the loads imposed upon them and afford protection to the railway. In clarification of this principle the document applies to earthworks both adjacent to and supporting the railway. The risk to train operations from slope failure is minimised so far as is reasonably practicable by implementing auditable examination, evaluation of the condition and maintenance procedures. RAILTRACK 3

6 Page 4 of 7 Withdrawn Document 5 Competency 5.1 The Infrastructure Controller shall ensure that the responsibilities of all persons responsible for the safe asset management of embankments, cuttings and natural slopes are clearly defined in writing and understood by these persons. 5.2 The skill, expertise and training of the persons carrying out examinations, evaluation of the condition or maintenance works shall be appropriate to the nature of the embankment, cutting or natural slope and the situation that could be reasonably expected. 5.3 GO/RT3260 gives additional requirements for competence management for safety critical work. 6 Requirements 6.1 Listing The Infrastructure Controller shall prepare and maintain a register of all embankments and cuttings with a difference in level between top and bottom greater than 3m whose failure could affect the safety of train operations. The Infrastructure Controller shall also include in the register all embankments and cuttings with a difference in level between top and bottom less than or equal to 3m where there is a known history of instability and whose failure could affect the safety of train operations. In addition all natural slopes where there is a known history of instability that could affect the safety of train operations shall be included in the register. The register shall indicate clearly those embankments, cuttings and natural slopes where signs of instability are known to be present. It is permissible for the register to be split into geographical areas so long as the register is complete. 6.2 Records of incidents For all those embankments, cuttings and natural slopes that are included in the register, the Infrastructure Controller shall set up procedures to record: all incidents of slope failure; all incidents of exceptional changes in the vertical or horizontal alignment of the track, including twist, except where changes in alignment are attributable to track maintenance. 6.3 Preliminary investigation For all those embankments, cuttings and natural slopes that are included in the register, the Infrastructure Controller shall carry out a desk study (including a search of historical records) for evidence of previous instability where this is considered to be appropriate. 6.4 Examinations of embankments and cuttings Content of examination of rock cuttings An examination of a rock cutting shall include noting signs of instability or slope failure such as cracks, movement, unstable blocks, or the accumulation of rock debris at the foot of the rock cutting. The examination shall also include noting the condition and deterioration of any strengthening devices and protective measures (for example rock anchor bolts, netting, toe walls). 4 RAILTRACK

7 Page 5 of Content of examination of soil embankments and cuttings An examination of a soil embankment or cutting shall include noting for signs of instability or slope failure such as: irregularities in the slope (for example bulges, depressions, cracks, back scars); toe heaves; tilting of signal posts, electrification masts, trees or fence-posts; signs of erosion; blocked or broken drains, culverts or spillways; infestation by burrowing animals; lack of, or significant reduction in, vegetation. Particular attention shall be given to the effectiveness of and changes to any drainage system, including ditches, at the top and / or bottom of a slope or on the face of a slope Frequency of examinations The Infrastructure Controller shall determine the frequency and detail of examinations (for example walkover, visual, photographic) based on: any recorded incidents of slope failure or exceptional changes in the vertical or horizontal alignment of the track; the results of any preliminary investigation; the result of previous examinations; the evaluation of condition of the embankment, cutting or natural slope. 6.5 Evaluation of condition of embankments and cuttings Content of evaluations The evaluation of condition shall include both the surface slope and the interior of the embankment, cutting or natural slope When evaluations of condition are required The Infrastructure Controller shall initiate an evaluation of the condition of an embankment, cutting or natural slope where a slope failure occurs that has affected or could have affected the safety of train operations. The Infrastructure Controller shall consider initiating an evaluation of the condition of the embankment, cutting or natural slope: after an examination; on the basis of evidence from a preliminary investigation or from historical records; after a report of exceptional changes in vertical or horizontal track alignment; when a significant increase in load to an embankment or cutting is proposed or discovered; when a significant increase in train speed, axle weight or tonnage is proposed; where there are signs of distress in any construction which supports a slope; where there is an adjacent watercourse; where the adjacent land is subject to the collection of surface water; after a report that surface drainage arrangements (including those on adjacent land owned or controlled by an outside party) have been altered in a way that could cause slope failure; where there are proposals for works to be carried out which are likely to affect the stability of an embankment, cutting or natural slope; where there are reports or visible signs of water running down or having run down cuttings, slopes or overflowing spillways; where there is evidence of infestation by burrowing animals. RAILTRACK 5

8 Page 6 of 7 Withdrawn Document 6.6 Action following evaluation of condition or reports Following an evaluation of the condition where a potential slope failure is identified, or following a report of a slope failure or exceptional change in the vertical or horizontal alignment of the track which is attributable to a slope failure or instability, the Infrastructure Controller shall: take appropriate action to reduce the risk to train operations to as low as reasonably practicable (ALARP). Appropriate actions to be considered shall include carrying out maintenance works, the imposition of a temporary speed restriction and closure of the line; consider arranging for monitoring, instrumenting and / or examination where appropriate, to ensure the continuing safety of train operations. 7 Neighbouring Earthworks 8 Inspections of Track Support 9 Records Where the Infrastructure Controller becomes aware of the instability of an embankment, cutting or natural slope owned or controlled by an outside party that could affect the safety of train operations, the Infrastructure Controller shall take appropriate action to safeguard train operations. The requirements for track inspections, including those relating to the track support, are given in GC/RT5021. The Infrastructure Controller shall ensure that the register of all embankments, cuttings and natural slopes together with records of all examinations, evaluations of the condition and remedial works are maintained. The requirements for management of records are described in GI/RT RAILTRACK

9 Page 7 of 7 References GA/RT6001 s Change Procedures GC/RT5021 Track System Requirements (Programmed to be issued February 2000) GI/RT7001 GO/RT3260 Management of Safety Related Records of Elements of the Infrastructure Competence Management for Safety Critical Work HM Railway Inspectorate Railway Safety Principles and Guidance Part 1 The Catalogue of s (or s CD ROM) gives the current issue number and status of the documents that are published by the Safety & Standards Directorate. RAILTRACK 7