Abstract

Track–bridge interaction (TBI) is an increasingly essential consideration for the design and operation of railway bridges, especially for the innovative bridge structure systems that constantly spring up over the years. This paper focuses on the characteristics of additional forces in continuous welded rails (CWRs) on the 3 × 70 m integral rigid-frame bridge of the Fuzhou–Xiamen High-Speed Railway, which is a novel high-speed railway (HSR) bridge structure system in China. The differential equations of rail stress and displacement are first investigated and an integrative analysis model comprising of rail, track, bridge and piers is then established. Secondly, the characteristics of representative additional forces are illustrated and the influences of different design parameters are discussed in detail. Furthermore, suitable rail fasteners, optimal layout schemes of adjacent bridges and reasonable stiffness of piers are also studied. The results indicate that the additional expansion force accounts for the largest proportion of additional forces in integral rigid-frame bridges and that resistance reduction obviously weakens the various additional forces caused by the TBI effect, while the broken gap of the rail increases greatly. Small resistance fasteners are recommended to be applied onto this new type of HSR line as these provide reductions in additional stresses of CWRs compared to WJ-8 fasteners. The additional rail stresses after adopting an adjacent span scheme of 4 × 32 m simply supported beams are less than the corresponding stresses in other schemes. The results also show that there is a strong correlation between the minimum threshold value of the pier stiffness and the longitudinal resistance of HSR lines for the integral rigid-frame bridge. This work could serve as a valuable reference for detailed design and safety evaluation of integral rigid-frame bridges.

Highlights

  • Track–bridge interaction (TBI) is an important phenomenon occurring between continuous welded rails (CWRs) and bridges that is a vital factor to take into account during the design, construction, and maintenance of high-speed railways (HSRs)

  • The general solution of the displacement and the additional force where u is the longitudinal displacement of rail; ∆ is the longitudinal displacement of the follows: bridge; the relative displacement ∆u = u − ∆; uS is the critical point of the displacement in the resistance model; N is the additional longitudinal force of the rail; E is the elastic λx stiffness

  • Timal layout schemes of adjacent bridges and the reasonable stiffness of piers, were studSeveral major conclusions can be drawn from this work as follows: ied

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Summary

Introduction

Track–bridge interaction (TBI) is an important phenomenon occurring between continuous welded rails (CWRs) and bridges that is a vital factor to take into account during the design, construction, and maintenance of high-speed railways (HSRs). The mechanism of stiffness track–bridge between rails and integral displacements, causing the rails to move towards thean beam ends.rigid-frame. = 0forces is theand fixedthe point where the displacement theadditional bridge under temperature rising is 0, magnitude and direction ofof the forces acting on the bridge resistance of the fasteners, sleepers, the track bed and other constraints, the rails’ di depending stiffness ofby piers. Addition, long-spanfor inteThough a few scholars have carried out studies on the interaction between CWRs and gral railway bridges, the suitable rail fasteners, optimal layout of ad gralrigid-frame rigid-frame railway bridges, the suitable rail fasteners, the optimalthe layout of adjacent rigid-frame bridges [21,25,26], the stress characteristics of the rails on the novel integral bridges and the reasonable stiffness of piers were studied. Forces acting on the bridge and the rail are determined by the relative displacement

Differential Equation
Project Introduction and Fine Element Model
Integrated
Parameter
Additional Expansion Force
10. Graphical
Rail-Broken
15. Displacements
Longitudinal Resistance
Influence
Influence of the Pier Stiffness
Conclusions

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