This document summarizes a student's research poster presentation on redeveloping the shoulder design for an embedded light rail track. The student investigated reasons for deterioration of the concrete shoulders on Dublin's light rail system and proposed alternative solutions. The poster described a case study of a section with deteriorated shoulders. It outlined negatives of the original reinforced concrete slab and concrete shoulder design, and presented a new design replacing the concrete shoulder with asphalt and adding angle brackets to enhance rail stability. Design calculations were provided to show the new design met strength requirements.

1. RESEARCH POSTER PRESENTATION DESIGN ©
2011
www.PosterPresentation
s.com
LUAS Embedded Track Shoulder
Redevelopment
 My thesis is focused on investigating the possible reasons that caused embedded
track concrete shoulder deterioration on LUAS tram network. And hence proposing
alternative solution to troublesome shoulder design.
 The aim of the design is to take account of all the aspects that may have caused
the shoulder breakage. At the same time, develop simple and viable solution to the
problem, that can be implemented on the streets of Dublin.
Introduction & Aims
Case Study
For my thesis I have chosen embedded track section at St. James’s Hospital.
Why is this section of particular interest ?
 It is one of the most effected concrete shoulder type sections around Dublin area.
 I had been personally involved in repair works on the section.
 Repair works had been undertaken in the past, but these have been extremely time
consuming and challenging without providing satisfactory results.
 Shoulder breakup on this section is likely to become an increasing maintenance
problem in future years.
Conclusion
 To provide a stable surface, less prone to wear and therefore resurfacing.
 To keep the rail in place with more stability, given no gauge bars or embedded
sleepers were provided.
 To protect ALH/Phoenix encapsulation.
 To eliminate differential settlements between the rail and surrounding surfaces.
 To avoid cracks that could occur in critical transition area.
At the end of my design I came to a conclusion that it is difficult to predict the effect on adjacent
pavement either it’s concrete or asphalt without providing adequate restraint to the outer rail.
Nevertheless, by providing lateral support it can be seen that the forces generated by the LRV are
highly unlikely to have an affect on adjacent road surface.
 The design is focused on replacing the concrete shoulder with asphalt. The aim is
to demonstrate that the removal of the concrete shoulder will not affect the rail in
terms of gauge and rail stability.
Wheel Load qk = 60 kN
Curve Radius R =25 m
Speed V =10 km/h =2.78 m/s
Dynamic Factor α = 1.5
Fcentrifugal = mV2/R
Fcentrifugal = 19 kN
Design A
Outer Rail Loading Parameters
NegativesWhy has it failed ?
Reinforced Concrete Slab (RCS) Design
Paul Trofimov DT004/3S Tutor: Joseph Kindregan
 No gauge bars/sleepers installed.
 Shoulder is made separately from RCS.
 Failure to maintain adequate bond between
RCS and shoulder.
 Concrete level is not accurate (Wheel-
pavement contact).
 Shoulder is not able to follow the rate of ware
of the top of the rail.
 Stray current issue.
 Noise and vibration.
 Concrete breaks and becomes loose.
 Time consuming construction.
 Difficult repair works.
 Aesthetic appearance of repaired
section.
RCS Plan View Stress Distribution
Inverted Flat Slab Design Reinforcement Detail
Why was The Shoulder Used ?
Embedded Track Type 1 Lines A-B-C
Distribution Steel:
As.min.=364mm2
As.prov.=449mm2
H10@175mm c/c
Tension Reinforcement:
As.req.=268mm2
As.prov.=646mm2 H12@175mm c/c
Distribution Steel:
As.min.=364mm2
As.prov.=449mm2
H10@175mm c/c
Design B
Axial Load kN =
Curve Radius
(m) Velocity (m/s) Velocity (km/h) Fcentr. (kN)
Overturning
FOSo
Sliding
FOSs
Overturning
Mo (kNm)
Resisting
Mr (kNm)
60.00 25.5 2.78 10 18.16 ✓ 1.65 ✗ 1.06 3.27 5.4
60.00 25.5 2.92 10.5 20.02 ✓ 1.50 ✗ 0.96 3.60 5.4
60.00 25.5 3.06 11 21.97 ✗ 1.37 ✗ 0.87 3.95 5.4
 The aim of the following design is to replace concrete shoulder with asphalt infill.
 It also involves installation of angle bracket against the outer rail, to enhance rail
stability.
 Liebig Expansion Anchor is used to make RCS-bracket connection (M20 Grade 8.8).
Fcentr. (kN)
Shear Capacity
Fv.rd. (kN) Fe (kNm)
Fmax. Group
(kN) Fmax. (kN)
Tension
Capacity
Ft.rd. (kN)
Liebig Anchor
φsNtf (kN)
Bearing
Capacity
Fb.rd. (kN)
Liebig Anchor Cocrete
cone failure capacity
ѯcφcNtc (kN)
Liebig Anchor
Clamping
Force/Slip/
Fatigue φ...Nti
(kN)
18.16 ✓ 188.60 0.91 30.78 15.39 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
20.02 ✓ 188.60 1.00 33.93 16.97 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
21.97 ✓ 188.60 1.10 37.24 18.62 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
24.01 ✓ 188.60 1.20 40.69 20.35 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
26.14 ✓ 188.60 1.31 44.31 22.15 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
28.37 ✓ 188.60 1.42 48.08 24.04 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
30.68 ✓ 188.60 1.53 52.00 26.00 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
33.09 ✓ 188.60 1.65 56.08 28.04 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
35.58 ✓ 188.60 1.78 60.31 30.15 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✓ 62.37 ✓ 67.92
38.17 ✓ 188.60 1.91 64.69 32.35 ✓ 176.00 ✓ 156.80 ✓ 217.00 ✗ 62.37 ✓ 67.92
Theory of Limit State Design: Design Action Effect ≤ Nominal Capacity
Tension Reinforcement over supports (Rail):
As.req.=86mm2
As.prov.=646mm2 H12@175mm c/c