Traffic loading on highway bridges

Transcription

1 Research Perspectives Traffic loading on highway bridges Peter Dawe ThomasTelford

2 Contents Author' s biography About 1'RL Foreword Acknowledgements Conversion table xi xiii xv xvii xix Chapter 1 Introduction Historical overview Scope of contents Choice of loading model Influences on loading rules Development of standards Future developments 7 References 10 Chapter 2 Historical review: Part 1, Concrete Institute Report Ministry of Transport Standard Loading Train, Ministry of Transport I'xjuivalent Loading Curve, BS 153 Standard specification for girder bridges, BS 153 Standard specification for girder bridges revision Code of practice for simply supported steel bridges, Ministry of War Transport Memorandum No. 577, References 20 Chapter 3 Historical review: Part 2, BS 153: Part 3A: Loading models Normal loading curve 22 =*>»

3 Research Perspectives Traffic loading on highway bridges Short-span members Concrete slabs Notional traffic lanes Abnormal loading Braking forces Footways Ministry of Transport Memorandum No. 771, Ministry of Transport Interim Memorandum (bridges) IM 10, BS 153: Parr 3A: Department of the I Environment Technical Memorandum (bridges) BL 5/ Interim design and workmanship rules Part 1: Loading and general design requirements, Department of Transport Technical Memorandum (bridges) BL 1/77, References 30 Chapter 4 Limit state design BS 5400: Part 2: Limit state design HA loading curve HB vehicle Application or HA and I IB loading Partial load factors Load combinations Centrifugal force Braking loads Skidding loads Collision loads Department of Transport, Departmental standard BD 14:82, Department of Transport's Interim revised loading specification, References 43 Chapter 5 Revision of HA Type loading 1. Short span Background 4r> 5.2 Methodology C&1! vehicle loading and impact Overloading Lateral bunching Derivation ot loading Future [European vehicles 51 References 52 Chapter 6 Revision of Type HA loading 2. Long span Background Outline of loading studv 56 IV

4 Traffic loading on highway bridges 6.3 Data used in study Vehicle weights and lengths Proportions of different vehicle types Variation in average vehicle weights through the day Spacing between vehicles Characteristics or traffic ams Vehicle lane selection Projections of traffic growth to Generation of traffic streams Determination of equivalent uniformly distributed load Method Normal distribution I Extremal distribution Lane load factors Sensitivity studies Percentages of heavy goods vehicles )am frequencies and duration Traffic flow rate Vehicle spacing Lane distribution Design values 66 References 68 Chapter 7 Composite version of BS 5400: Part Background Type HA loading Type HB loading I IA lane factors Load combinations and partial factors Accidental wheel loading Loads due to vehicle collisions with parapets Secondary live loads Department of Transport implementation Design manual for roads and bridges, BD 37/01 74 References 74 Chapter 8 Short-span assessment loading Background Outline of methodology Static load models Vehicle data Traffic modelling Dynamic load model Data Dynamic effect model Probabilistic load model 79

5 Research Perspectives Traffic loading on highway bridges 8.6 Reliability analysis Lateral bunching Load reduction factors 80 References 82 Chapter 9 Loading for assessment Introduction Technical Memorandum (bridges), BIE Background Vehicle trains Application of vehicle trains Public service vehicles Load distribution Operation bridgeguard Technical Memorandum (bridges) BE 3/ Departmental standard BD 21/ Background Reduced loadings Single axle and single wheel loads Application of loading Centrifugal effect Advice note BA 16/ Amendment No. 1 to BD 21/ Background Assessment loading Wheel loading Special structures Lane factors Design manual for roads and bridges BD 21/ Design manual for roads and bridges BD 21/ Adjustment factors Special structures Lane factors Design manual for roads and bridges BA 16/ Design manual for roads and bridges BD 21/01 96 References 96 Chapter 10 Abnormal loading Introduction Regulation of abnormal vehicles STGO vehicles SO vehicles Review of studies of abnormal vehicle loading Highway bridge loading appraisal Long span bridge loading: Contractor Report Rei'alidafion of traffic loading for abnormal vehicles 104 VI

6 Traffic loading on highway bridges 10.6 Loading models for STGO vehicles Loading model for SO vehicles Development of loading model for abnormal vehicle effects Background Shortcomings of existing HB model Development of SV loading model Overload factor (OF) Dynamic amplification factor (DAF) Partial load factors Masonry arches Design manual for roads and bridges BD 86/ Background Loading Application Special structures Reserve factors HB-to-SV conversion charts Management ot STGO vehicle movements 115 Reterences 115 Chapter 11 Collision loads Introduction FEarly requirements Bridge rehabilitation programme Study of heavy goods vehicle collisions with highway structures Design manual for roads and bridges BD 48/ Design manual for roads and bridges BD 60/ Computer simulation of heavy goods vehicles collisions with bridges 121 References 123 Chapter 12 Control of traffic loading Introduction Vehicle regulations F.uropean vehicles Traffic loading restrictions Weight restrictions 130 References 131 Chapter 13 Eurocodes Background Development of FNV FNV [2], scope and contents Load Model Load Model Load Model = > VII

7 Research Perspectives Traffic loading on highway bridges Load Model Derivation of Load Models 1 and Background Methodology [Extrapolation methods Dynamic effects Loading patterns Influence lines Calibration ot Load Model 1 Load Model Application of loading Lane widths Partial live load factors Load combinations Reduction factors 13.6 Other types of loading Accidental loads Braking Centrifugal force References Chapter 14 National Application Document (NAD) Background National requirements Calibration studies Initial parametric calibrations Scope Congested traffic Flowing traffic Adjustment factors--load Model Adjustment factors Load Model Reduction factors Abnormal vehicles Load Model Final parametric calibrations Scope Adjustment factors (ft) Reduction factors ((/>) Abnormal vehicles Load Model Secondary loads braking Secondary loads centrifugal forces Accidental loads collision forces on piers Accidental loads vehicles on footways Published version of the UK NAD Introduction Partial safety factors (-")) Adjustment factors (a) VIM

8 Traffic loading on highway bridges Reduction factors (i,. 1 ) Tables of factors 157 References 157 Appendix Use of OPTAX program 159 Al Introduction 159 A2 Vehicle trains 159 A3 Vehicle spacing 160 A4 Impact factors 160 Reference 160 Index 161 = >*