Tunnels: Inspection, Assessment and Maintenance

Table of Contents:
Summary Acknowledgements Glossary Abbreviations List of boxes List of figures List of tables References 1 Introduction and background 1.1 Background 1.2 Purpose and scope of work 1.3 Application 1.4 Issues dealt with in this guide 1.5 How to use this guide Construction and behaviour 2.1 Tunnel construction 2.2 Construction shafts 2.3 Masonry linings 2.4 Metal linings 2.5 Pre-cast concrete linings 2.6 Tunnel performance 2.7 Shaft performance 3 Tunnel asset management 3.1 The need for tunnel management 3.2 Special requirements 3.3 Loss of performance and its consequences 3.4 Managing tunnel maintenance 3.5 Tunnel management procedures and tools 3.6 Health and safety, and environmental management 3.7 Tunnel operational safety and fire risks 3.8 Management of tunnel shafts 3.9 Management of closed and disused tunnels 4 Condition appraisal 4.1 Types and sources of information 4.2 Desk studies and existing information 4.3 Visual inspection 4.4 Tunnel investigation 4.5 Tunnel monitoring 4.6 Preparing for inspections and investigations 4.7 Location and inspection of tunnel shafts 4.8 Interpretation of inspection and investigation data 4.9 Structural assessment of tunnels 4.10 Reporting on and interpreting asset condition 5 Selecting and carrying out works on tunnels and shafts 5.1 Selection, planning and preparation for works 5.2 Tunnel repair measures 5.3 Routine (preventative) maintenance 5.4 Remedial repairs 5.5 Strengthening and structural enhancement 5.6 Treatment of tunnel shafts 6 Water ingress and control 6.1 General considerations 6.2 Passive measures 6.3 Active measures 6.4 Grouting 6.5 Alternative measures 7 Recommendations and future needs 7.1 Recommendations for good practice 7.2 Areas requiring further research and future needs Appendix A1 Case studies Appendix A2 Sources of existing information A2.1 Sources of historical information A2.2 Sources of geological and hydrogeological information A2.3 Aerial photographs A2.4 Utilities and services A2.5 Walkover survey Appendix A3 Visual inspection procedures and observations A3.1 Preparation A3.2 Observation and recording Appendix A4 Inspection, investigation and monitoring techniques A4.1 Inspection, mapping and simple on-site tests A4.2 Sampling and testing techniques A4.3 Specialist non-destructive investigation techniques A4.4 Techniques for monitoring Appendix A5 Detection and location of hidden shafts A5.1 Multi-phase approach to shaft location Appendix A6 Investigation and assessment of unlined tunnels and shafts A6.1 Desk study A6.2 Reconnaissance visit A6.3 Detailed survey A6.6 Rock mass classification systems Appendix A7 Guidance on structural assessment A7.1 Limit state assessment A7.2 Assessment principles A7.3 Assessment worked examples