Design Concrete Sleepers

Design of concrete sleepers November 22nd 2012

est une Société du groupe

SCOPE

• State of the Art • New European Standard EN 13230 Part 6 “Concrete sleepers – Design” • SPENNCON means for concrete sleeper design

• “Smart sleepers” with cast-in sensors


Sleepers design – State of the Art There is existing documentation for the design of Concrete sleepers Best known are:  UIC leaflet 713 R dated November 2004 « Design of monoblock concrete sleepers »  AREMA Chapter 30 « Ties »

There is a general agreement among European experts that these calculation methods:  Are efficient for determining bending moments at rail seat section  Are not efficient for determining bending moments at centre section


New European Standard EN 13230 Part 6 “Concrete sleepers – Design New European Standard EN 13230 Part 6 « Concrete sleepers - Design » will be submitted for final vote from all European, Standard bodies in 2013 Standard provides 2 ways for designing concrete sleepers:  Experimental method from successful experience in tracks  Theoretical method with the use of finite elements calculation In addition, both methods can be mixed


New European Standard EN 13230 Part 6 “Concrete sleepers – Design Effect of wheel load to the sleeper

Levels of bending moments in the sleeper


New European Standard EN 13230 Part 6 “Concrete sleepers – Design Steps for the experimental method


New European Standard EN 13230 Part 6 “Concrete sleepers – Design Steps for the theoretical method


New European Standard EN 13230 Part 6 “Concrete sleepers – Design

Design model using the elastic beam on elastic foundation


SPENNCON means for concrete sleeper design First step is to check that: geometry of the sleeper + position/quantity of prestressing tendons + manufacturing process will fulfill required bending moments For this purpose, Excel sheet at SPENNCON for: Calculation

of losses according to Eurocode 2 for prestressing, concrete shrinkage, etc Takes into account: – Position of each prestressing tendon – Concrete strength – Manufacturing process – Etc



SPENNCON means for concrete sleeper design Second step in to check homogeneity of the prestress inside the concrete sleeper For this purpose, Finite Element tool at SPENNCON for: Calculation

run on the CAO 3D model Help for the design


New “Smart sleepers” with cast-in sensors New European Standard « Concrete sleepers and bearers – Design » with many European Railway Administrations Accurate

knowledge for sleeper « real » bending moments at rail

seat Little knowledge for sleeper « real » bending moments at centre section Little knowledge for bearers « real » bending moments

Proposal from CONSOLIS Rail Branch is to measure « real » bending moments in track with the use of dedicated sleepers/bearers


New “Smart sleepers” with cast-in sensors

• State of the art is to use strain gauges for the measurement of stresses in the concrete sleepers. • Strain gauges are glued on the lateral surface of the sleepers • Durability of gauges is reduced


“Smart sleepers” with cast-in sensors

Vertical sensors for load measurement

Horizontal sensors for bending moment measurement

• System is to use standard sleepers with sensors embedded in the concrete

• Why a fiber optical sensor (rather than a strain gauge)  Cast into the concrete  Insensible to electromagnetic perturbation  Dynamic measures up to 15kHz  Long sensor


“Smart” sleepers with cast-in sensors

• Goal: provide to our clients a tool for better understanding of the track behaviour Utilization

for R&D programs

– Provides measured values for the coefficients proposed in the EN standard 13230-6 “Concrete sleepers and bearers – Design” • Wheel load distribution on sleepers • Effect of speed on sleepers • Effect of rail pad stiffness on sleepers • Measurement of bending moments in bearers – Measure the effect of USP, Soft rail fastening, etc – Measure the effect of temperature on resilient materials (Rail pads, USP, etc) – Measure the influence of maintenance operation (rail grinding, ballast tamping…) Utilization

for track monitoring with measurement of the sleeper bearing irregularities on ballast est une Société du groupe

Thanks for your attention


Design Concrete Sleepers

Recommend Documents