Railway Bridge Maintenance, Second Edition

Contents Foreword to the second edition ix
Preface xi
Acknowledgements xiii
About the author xv
Introduction xvii

01 . . . . . . . . . . . . . . . . . . . . . . .Historical records 1
02 . . . . . . . . . . . . . . . . . . . . . . .Deterioration 7
2.1. Exposure and weathering 7
2.2. Defects arising from faults in design and detail 12
2.3. Cast iron bridges 21
2.4. Wrought iron bridges 29
2.5. Defects arising from faulty materials and
workmanship 38
2.6. Overloading 51
2.7. Fatigue 57
2.8. Past neglect 58
2.9. Bridge strike damage 59
2.10. Other accidental and malicious damage 60
03 . . . . . . . . . . . . . . . . . . . . . Assessment of strength and carrying capacity 61
3.1. Assessment 62
3.2. Assembling information 63
3.3. Analysis 64
3.4. Stresses 65
3.5. Testing 67
3.6. Capacity and capability 67
3.7. Special permissions 68
3.8. Arches 69
3.9. Tests 71
References 76
04 . . . . . . . . . . . . . . . . . . . . .. Examination 77
4.1. Priorities and programming 77
4.2. Selection and training of bridge examiners 81
4.3. Preparation for examination 82
4.4. Intervals between examinations 84
4.5. Risks to health 88
05 . . . . . . . . . . . . . . . . . . . . . . Preventive maintenance 89
5.1. Additional material 89
5.2. Concrete encasement 91
5.3. Metal coatings 97
5.4. Painting 97
5.5. Cathodic protection 99
5.6. Waterproofing and drainage 100
5.7. Pointing 102
5.8. Cleaning 102
5.9. Bird infestation 103
5.10. Vegetation 103
5.11. Preservation of timber 104
References 105
06 . . . . . . . . . . . . . . . . . . . . . . Economics 107
6.1. Detailed estimates 108
6.2. Rough estimates 110
6.3. Present and future costs 111
6.4. Comparison of alternatives 114
07 . . . . . . . . . . . . . . . . . . . . .. Asset management 119
7.1. What is asset management? 119
7.2. Historic context 119
7.3. The asset management system 120
7.4. Asset information 120
7.5. Optimisation 121
7.6. Conclusion 121
Reference 122
08 . . . . . . . . . . . . . . . . . . . . . Diagnosis and treatment 123
8.1. Mining subsidence 123
8.2. Substructures 124
8.3. Arches 135
8.4. Superstructures 142
09 . . . . . . . . . . . . . . . . . . . . . . Use of new materials 161
10 . . . . . . . . . . . . . . . . . . . .. . .Remote condition monitoring 165
10.1. What can be measured with discrete
sensors? 166
10.2. Risks and pitfalls: understanding structural
behaviour 166
10.3. Instrumenting for likely structural behaviour 167
10.4. Monitoring intervals (aliasing) 167
10.5. Relating loss of strength with change
in stiffness 167
10.6. Discrete sensors 168
10.7. Strain 168
10.8. Displacement 169
10.9. Robotic total station survey 169
10.10. Acceleration 169
11 . . . . . . . . . . . . . . . . . . . . . . Case studies 171
11.1. Case study 1: GSW 161/244 Enterkin Burn
and GSW 161/222 Crawick Viaducts –
arch barrel fracture 171
11.2. Case study 2: NOG1/6 Old Beck Bridge –
wing wall failure 177
11.3. Case study 3: ATL/1296 Denmark Hill
overline bridge – failure of concrete
encasement 180
11.4. Case study 4: ECN2 090/080 Invertiel
Viaduct – parapet failure 184
11.5. Case study 5: EGM1 070/130 Cathedral Street
overbridge – failure of rolled wrought
iron sections 186
11.6. Case study 6: CEJ 0 m 9.5ch Cardiff
spandrel wall failure 191
11.7. Case study 7: MLN1 106 m 4.5ch
Beckford Road overbridge – root jacking
of masonry 194
Index 199