Upload
trinhtram
View
223
Download
1
Embed Size (px)
Citation preview
Posibilities and advances of the ERS system for bridge restoration
Pavel Ryjáček
CTU IN PRAGUE, FACULTY OF CIVIL ENGINEERING DEPARTMENT OF STEEL AND TIMBER STRUCTURES
Introduction
• Description of the ERS system • Results from the tests, performed recently at the
CTU • Application of the results on the Starý Most,
Bratislava • Bridge project description • ERS application • Numerical analysis and verification • Construction of the bridge
• Conclusions
ERS – Embedded rail system
• Perspective rail fastening system • Suitable for renovation of bridges, excellent noise absorption • Low buckling risk, low structural depth • Insufficient information for the structural analysis of bridges • Lack of longitudinal resistance parameters (very limited knowledge
in UIC 774-3) • The rail is embedded by PUR elastic material, filled with cork
aggregate
Bridge – rail interaction
Motivation - actual problems: • Continuous welded rail on the bridge – results in the combined
response and coupling between the bridge and the rail • Parameters affecting B/R interaction:
• Structural and geometrical properties of both the bridge and the rail • Bridge span arrangement • Bridge deck type (type of fastening) • Vertical and horizontal loads – traffic, temperature change
Bridge – rail interaction
Motivation - actual problems: • Leads to the horizontal reactions and additional stresses in the rail • Risk – rail brake – rail buckling • Insufficient interaction data for the numerical models, especially for
ERS
ERS – laboratory test
Objectives: • Simulate the behaviour of the CWR, loaded by various vertical rail
wheel load (0, 40, 80, 125 kN) and longitudinal displacement from temperature change
• Simulation based on the typical bridge stringer, L=2500 mm, loaded as a simply supported beam
• Simulate on the numerical model and perform: • Longitudinal resistance parameters under different load • Establish the load pattern for the design of the supporting
substructure
ERS – laboratory test
• The rail is embedded by PUR elastic material, filled with cork aggregate
• Embedded in the steel channel, representing the steel bridge • Loaded vertically, horizontally, measures stresses, displacement
Support
Horizontal
force
Vertical force
ERS – 3D FEM simulation
• 3D FEM model created, verified and validated • Based on the model, the load distribution principle was analysed
and design criteria established
ERS – 3D FEM simulation
• 3D FEM model created, verified and validated • Comparison of the model and reality in the end part
ERS rail – main results
• Surprisingly, opposite to the standard UIC 774-3, the longitudinal resistance is not affected by the vertical force, and it is slightly lower under the load!
ERS rail – main results
• Important factor is the speed of the load – high speed (braking, acceleration) = higher longitudinal resistance, low speed (temperature change) – smaller longitudinal resistance
ERS rail – main results
• Longitudinal resistance k significantly (app. 2x) higher, than values in the UIC 774-3 code
• Even for the longitudinal displacement of 19 mm no failure of the adhesive layer observed, limited problems only at the end of the resilient pad and the rail bottom part.
Unloaded track (kN/mm) Loaded track(kN/mm)
UIC 774-3 13 19
Test results 33.01 30.66
ERS rail – main results
• Based on the numerical model, the vertical pressure of the rail on the main bridge structure analysed
• The corresponding effective width and length establishes, as a guide for the analysis
ERS rail – main results
• The important is the impact of the ERS on the steel structure stresses
• There is the „reinforcing“ effect – the reduction of the stresses in the upper flange
• Useful for the application on the old bridges
Laboratory work conclusion • Many important information and knowledge obtained from the
work and tests • Next work will be focused on the speed and temperature
impact on the longitudinal resistance • Results recently (2015) directly applied on the widest
application of the ERS in middle Europe – „Starý most“ – 464 m long, Bratislava, Slovakia
Starý most project description
• The bridge was demolished during WWII by retreating german army
• After the war, the temporary steel bridge was built by german captured soldiers by Red army
• It has served till 1972 as a only bridge in Bratislava, with the tram and 2 lanes road
Starý most project description
• Project owner: City of Bratislava • Contractor: Eurovia SK, Eurovia CZ • Designer: ALFA 04, Reming Consult • 2 tram train tracks, 2 pedestrian walkways
Starý most project description
• Total legth 465,4 m, span 32+107+137+75+75+32 m
Starý most - ERS application
• Specific rail requirements: • Conventional tram in Bratislava, with gauge 1000 mm • Proposed new Tram-Train vehicle, with gauge 1435 mm • This resulted in multiple rail solution, in the urban area • The ERS system was proposed to be applied here
Starý most - numerical analysis
• Analysis of the ERS behaviour with interaction with the bridge • Fulfilment of the EN 1991-2 requirements for the stress and
displacement limits was verified on the 2D nonlinear model, the coupling interface was modelled by the nonlinear hinges
Starý most - numerical analysis
• The temperature difference between the rail and bridge results in the axial force in the rail:
• Impact of the vertical load on the axial force in the rail:
Breathing end Breathing end
Starý most - numerical analysis
• Detail analysis of the transition zone by expansion joint • 3D solid model, loaded by longitudinal displacement (from
temperature variation) and wheel load
• Impact of the vertical load on the axial force in the rail:
Starý most - numerical analysis
• Resulting stresses showed very good behaviour of the ERS • Allowable stesses were only exceeded in the small regions in PUR
blocks • Reccomended to use full resin VA-60 in the breathing end zone, in
between the PUR foam blocks can be used.
Starý most – construction process
• Steel structure erection by use of longitudinal launching
Starý most – construction process
• Steel structure erection by use of longitudinal launching
Starý most – construction process
• Steel structure erection by use of longitudinal launching
Starý most – construction process
• Steel structure erection by use of longitudinal launching
Conclusion
• ERS – perspective rail fastening system • The design knowledge developed and tested in
the laboratory • The results free to the public • The ERS solution in the fast development –
recently many important applications worldwide
Thank you for your attention
Research reported in this paper was supported by Competence Centres program of Technology Agency of the
Czech Republic (TA CR), project Centre for Effective and Sustainable Transport Infrastructure (no. TE01020168).
The authors greatly acknowledge the support and help from Edilon Sedra Inc. and SDS EXMOST spol. s.r.o..