Book Description

This publication provides infrastructure owners, consulting engineers, contractors and maintenance managers with guidance on the management, condition appraisal, maintenance and repair of drystone retaining walls. It is based on a detailed review of published literature and infrastructure owners' procedures, consultation with experts and practitioners within the field.

The purpose of this publication is to present good practice, provide a guide for routine management, recommend assessment, maintenance and repair strategies to give value for money and help knowledge sharing.

This publication is divided into ten chapters, each including information and guidance on particular aspects of drystone retaining walls, followed by appendices with detailed information for practitioners including case studies demonstrating good practice.

200 pages

Contents: Executive summary, Acknowledgements, List of figures, List of tables, Glossary, List of acronyms and abbreviations, 1 Introduction and background, 1.1 Background, 1.2 Purpose and scope of work, 1.3 Application, 1.4 A historical perspective, 2 Management of drystone retaining walls, 2.1 The need for asset management, 2.2 Special requirements, 2.3 Managing drystone wall maintenance, 2.4 Safety and environmental management, 2.5 Drystone retaining wall Information requirements, 2.6 Whole life asset costs, 3 Understanding the stability of drystone retaining walls, 3.1 Explaining the stability of drystone retaining walls, 3.2 Water behind drystone retaining walls, 3.3 The properties of the retained ground or backfill, 3.4 Wall geometry, structure and stone properties, 3.5 Foundation stability, 3.6 Changed circumstances, 4 The inspection and qualitative assessment of drystone retaining walls, 4.1 General, 4.2 Current procedures for the inspection and assessment of retaining structures, 4.3 Methods of inspection and assessment, 4.4 Safety and responsibility, 5 Maintenance, 5.1 Background, 5.2 Maintenance planning, 5.3 Organising and managing maintenance, 5.4 Maintenance operations, 5.5 The cost of maintenance and renewal, 5.6 Environmental aspects, 6 Repairing drystone retaining walls, 6.1 Pointing, 6.2 Grouting, 6.2.1 Soil nailing, 6.3 Thickening the retaining wall, 6.4 Permanent and temporary buttressing, 6.5 Embankments, 6.6 Rebuilding in drystone, 6.7 Evaluating the stability of repaired structures, 6.8 Defining safety – factors of safety, 7 Replacing drystone retaining walls, 7.1 Mass concrete retaining walls faced with natural stone, 7.2 Reinforced concrete retaining walls faced with natural stone, 7.3 Some other solutions faced with natural stone, 8 Research and development, 8.1 Previous engineering studies, 8.2 Current research, 8.3 Future research and development, 9.1 Summary and recommendations, 9.2 Recommendations for good practice, 10 References, Appendix A.1 Literature review, A.1.1 Ground pressures on retaining walls, A.1.2 The literature on drystone retaining walls, A.1.3 TRL limited reports, Appendix A.2 Extracts from BD 21/01 and BA16/97 dealing with the assessment of drystone retaining walls, Appendix A.3 Examples of inspection reporting for drystone retaining walls on highways, A3.1 The Bradford approach, A3.2 The Gwynedd approach, A3.3 The concluding remarks, Appendix A.4 The stability of an existing masonry retaining wall and its strengthening, A.4.1 Assessment of an existing retaining wall, A.4.2 Strengthened using soil nails, A.4.4 Strengthened by grouting behind the retaining wall, A.4.5 Strengthening by thickening the retaining wall, A.4.6 Strengthening where only the height of a retaining wall is known, A.4.7 Concluding remarks, Appendix A5: Analysis of Nant Ffrancon wall according to the principles of BS8002, A5.1 Background, A5.2 Soil and highway loading, A.5.3 Equilibrium of the wall: sliding, A.5.4 Toppling and base bearing failure, A.5.5 Strengthening using soil nails, A.5.6 Strengthening by grouting behind the retaining wall, A.5.7 Strengthening by thickening the retaining wall, Appendix A.6 Case histories