ROADS2RAILSInnovative new concept for asphalt based railway construction

Tulika Bose

PhD student

Russel da Silva

Senior Consultant Permanent-Way

ROADS2RAILS Project Group

Arkil

Atkins

Danish Technological Institute

Rail Net Denmark

Technical University of Denmark

Financially supported by Innovation Fund Denmark

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ROADS2RAILS Ballasted Track

Components:

Ballast

SleeperRail

Subgrade

Subballast

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ROADS2RAILS Ballasted Track

Ballast:

Granular materials [31,5mm - 50mm].

Vertical, lateral and longitudinal resistance.

Easy maintenance.

Track drainage.

Subballast

Ballast

SleeperRail

Subgrade

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ROADS2RAILS Ballasted Track

Subballast:

Lower layer of superstructure.

Hard surface - SG II 0/31,5.

Fast draining gravel - 0/8, 0/11,2 or 0/16.

Track drainage.

Separation.

Frost protection.Subballast

Ballast

SleeperRail

Subgrade

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ROADS2RAILS Ballasted Track

Ballast Fouling:High cyclic stress levels

Ballast

degradation

Ballast-

fouling

Frequent maintenance

(a)New ballast

(b)Partially-fouled

ballast

(c)Fully-fouled

ballast

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ROADS2RAILS Ballasted Track

Ballast fouling

Reduced track

drainage

Lowered resistance

Concerns:

Frequent and costly maintenance.

Non-availability of the track.

Delays.

Frequent maintenance

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ROADS2RAILS Goals

Demands from rail transportation:

Faster trains.

Heavier axle loads.

Increased train frequencies.

Safe

Comfortable

Reliable

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ROADS2RAILS Alternative Trackforms

Ballasted track

Subballast

Ballast

SleeperRail

Subgrade

Subballast

Ballast

SleeperRail

Subgrade

Asphalt

Asphalt combination

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ROADS2RAILS Alternative Trackforms

Subballast

Ballast

SleeperRail

Subgrade

Asphalt

Asphalt combination

RailSleeper

Asphalt

Ballast

Subgrade

Asphalt underlayment

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ROADS2RAILS Alternative Trackforms

Rail

Aggregate base

Concrete

Subgrade

Slab track system

Aggregate base

Asphalt

SleeperRail

Subgrade

Asphalt overlayment

Asphalt based solution

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ROADS2RAILS Project Idea

Subballast

Ballast

SleeperRail

Subgrade

Aggregate base

Asphalt

SleeperRail

Subgrade

Replacement of granular ballast and subballast with asphalt layers.

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ROADS2RAILS Expected Advantages

1. Structural

Improved:

a. Subgrade moisture protection.

b. Load spreadability.

c. Bridging over weak spots.

2. Environmental

a. Lower vibration and noise levels.

b. Recyclability.

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ROADS2RAILS Expected Advantages

3. Economic

Lower:

a. Maintenance.

b. Life cycle cost.

Boost Danish asphalt industry.

4. Others

a. Expertise in asphalt work.

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ROADS2RAILS Challenges

More detailed geotechnical investigation.

Lateral force transfer between sleeper and asphalt.

Maintenance, when needed.

Aggregate base

Asphalt

Sleeper

Rail

Subgrade

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WP1

WP2

WP3WP4

WP5

WP6

Structural Model

Mix Design

Experimental set-up

Environmental Factors

Dissemination Activities

Project Management

ROADS2RAILS Work Packages

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ROADS2RAILS Work Packages

WP1

WP2

WP3WP4

WP5

WP6

Structural Model

Mix Design

Experimental set-up

Environmental Factors

Dissemination Activities

Project Management

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ROADS2RAILS Structural model

1. 2-D Numerical Finite Element model

Rail , EI

Support, k

P

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ROADS2RAILS Static Analysis

0,20

0,40

0,60

0,80

1,00

1,20

1,40

20,0 40,0 60,0 80,0 100,0 120,0

Dis

pla

cem

ent,

mm

Track modulus, MPa

Variation of Vertical displacement with Track Modulus

Analytical

Numerical

-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

-10,0 -5,0 0,0 5,0 10,0

Dis

pla

cem

ent,

mm

Distance along beam, m

k =80 MPa

k =100 MPa

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ROADS2RAILS Structural model

1. 2-D Numerical Finite Element models

Rail , m, EI

Support, k

P, V

50

100

150

200

250

20,0 40,0 60,0 80,0 100,0 120,0

Fun

dam

enta

l Fre

qu

en

cy, H

z

Track modulus, MPa

Variation of Fundamental Frequency with Track Modulus

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ROADS2RAILS Dynamic Analysis

-0,8

-0,6

-0,4

-0,2

0,0

0,2

-0,06 -0,04 -0,02 0,00 0,02 0,04 0,06

Dis

pla

cem

ent,

mm

Time, sec

k=80MPa

V=400m/secV=200m/secV=100m/sec

-1,2

-1,0

-0,8

-0,6

-0,4

-0,2

0,0

0,2

-6,0 -4,0 -2,0 0,0 2,0 4,0 6,0

Dis

pla

cem

ent,

mm

Relative distance between mid-point on beam and load, m

V=200m/sec

k=120MPak=80MPak=40MPa

ROADS2RAILS Structural model

2. 3-D Numerical finite element layered half-space models.

Challenges:

o Material Properties

Temperature

Rate of loading

Stress dependency

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ROADS2RAILS Structural model

2. 3-D Numerical finite element layered half-space models.

Challenges:

o Analysis

Boundary conditions

Mesh refinement

Computational cost

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ROADS2RAILS Work Packages

WP1

WP2

WP3WP4

WP5

WP6

Structural Model

Mix Design

Experimental set-up

Environmental Factors

Dissemination Activities

Project Management

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ROADS2RAILS Experimental Set-up

Basic sketch of test set-up

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ROADS2RAILS Experimental Set-up

1. Sleeper: Optimized to suit the new system.

2. Asphalt: Designed layers of asphalt.

3. Base layers: Granular layers.

4. Mattress: To mimic subgrade response.

Components:

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ROADS2RAILS Work in Progress….

1. WP1: Finite element model to be developed.

2. WP2: Novel asphalt type to be developed and tested.

3. WP3: Test facility to be constructed and instrumented.

4. WP4: LCC analysis.

5. WP5: Dissemination activities.

Contact:

DTU Civil Engineering ATKINSTulika Bose: PhD student Russel da SilvaE- Mail: tulbo@byg.dtu.dk E- Mail: Russel.da.Silva@atkinsglobal.com