Ballastless Tracks

Editorial IX About the authors XI 1 Introduction and state of the art 1 1.1 Introductory words and definition 1 1.2 Comparison between ballasted track and ballastless track 1 1.3 Basic ballastless track types in Germany – the state of the art 3 1.3.1 Developments in Germany 4 1.3.2 Sleeper framework on continuously reinforced slab 5 1.3.3 Continuously reinforced slab with discrete rail seats 7 1.3.4 Precast concrete slabs 7 1.3.5 Special systems for tunnels and bridges 9 1.3.6 Further developments 9 1.3.7 Conclusion 11 1.4 Ballastless track systems and developments in other countries (examples) 11 References 15 2 Design 17 2.1 Basic principles 17 2.1.1 Regulations 17 2.1.2 Basic loading assumptions 18 2.2 Material parameters – assumptions 19 2.2.1 Subsoil 19 2.2.2 Unbound base layer 20 2.2.3 Base layer with hydraulic binder 21 2.2.4 Slab 23 2.3 Calculations 24 2.3.1 General 24 2.3.2 Calculating the individual rail seat loads 24 2.3.3 Calculating bending stresses in a system with continuously supported track panel 28 2.3.4 System with individual rail seats 28 2.3.5 Example calculation 32 2.4 Further considerations 35 2.4.1 Intermediate layers 35 2.4.2 Temperature effects 35 2.4.3 Finite element method (FEM) 36 References 37 3 Developing a ballastless track 39 3.1 General 39 3.2 Laboratory tests 40 3.2.1 Rail fastening test 40 3.2.2 Testing elastic components 41 3.2.3 Tests on tension clamps 42 3.3 Lateral forces analysis 42 References 43 4 Ballastless track on bridges 45 4.1 Introduction and history 45 4.1.1 Requirements for ballastless track on bridges 45 4.1.2 System-finding 45 4.1.2.1 Geometric restraints 47 4.1.2.2 Acoustics 48 4.1.2.3 Design 48 4.1.3 System trials and implications for later installation 49 4.1.4 Measurements during system trials 50 4.1.4.1 Braking tests 50 4.1.4.2 Acoustic properties after installing a resilient mat 50 4.1.4.3 Deflection of the slab 51 4.1.4.4 Summary of system trials 51 4.1.5 Regulations and planning guidance for laying ballastless track on bridges 51 4.1.6 The Cologne–Rhine/Main and Nuremberg–Ingolstadt lines 51 4.1.7 VDE 8 – new forms of bridge construction 52 4.2 Systems for ballastless track on bridges 53 4.2.1 The principle behind non-ballasted ballastless track on long bridges 53 4.2.2 Ballastless track components on long bridges 54 4.2.2.1 Rail seats 54 4.2.2.2 Slab 56 4.2.2.3 Cam plate 56 4.2.2.4 Separating layer 57 4.2.2.5 Protective concrete 58 4.2.3 Ballastless track on short bridges 58 4.2.4 Ballastless track on long bridges 59 4.2.5 The bridge areas of ballastless tracks 61 4.2.6 End anchorage 62 4.3 The challenging transition zone 62 4.3.1 General 62 4.3.2 The upper and lower system levels 62 4.3.3 Interaction of superstructure and bridge 63 4.3.4 General actions and deformations at bridge ends 64 4.3.5 Summary of actions 66 4.3.6 Supplementary provisions for ballastless track on bridges and analysis 66 4.3.7 Measures for complying with limit values 68 4.3.8 Summary, consequences and outlook 69 References 70 5 Selected topics 73 5.1 Additional maintenance requirements to be considered in the design 73 5.2 Switches in slab track in the Deutsche Bahn network 73 5.3 Slab track maintenance 76 5.4 Inspections 76 5.4.1 General 76 5.4.2 Cracking and open joints 77 5.4.3 Anchors for fixing sleepers 78 5.4.4 Loosening of sleepers 78 5.4.5 Additional inspections 79 5.5 Slab track repairs 79 5.5.1 Real examples of repairs 79 5.5.2 Renewing rail supports 79 5.5.3 Repairing anchor bolts 80 5.5.4 Dealing with settlement 80 5.5.5 Defective sound absorption elements 80 5.6 Drainage 81 5.6.1 General 81 5.6.2 Draining surface water 81 5.6.3 Central drainage 81 5.6.4 Strip between tracks 81 5.6.5 Cover to sides of slab track 82 5.7 Transitions 82 5.7.1 General 82 5.7.2 Transitions in substructure and permanent way 82 5.7.3 Welding and insulated rail joints 83 5.7.4 Transitions between bridges/tunnels and earthworks 83 5.7.5 Transitions between slab and ballasted track 83 5.7.6 Transitions between different types of slab track 84 5.8 Accessibility for road vehicles 84 5.8.1 General 84 5.8.2 Designing for road vehicles 84 5.8.3 Designing for road vehicle loads 85 5.9 Sound absorption elements 86 5.9.1 General 86 5.9.2 Construction and acoustic requirements 86 5.9.3 Special requirements for materials and construction 86 References 87 Index 89