SLAB TRACK

SLAB TRACK
SYSTEM ÖBB–PORR ELASTICALLY SUPPORTED TRACK BASE PLATE

GENERAL
The slab track (ST), system ÖBB–PORR elastically supported
track base plate, has been jointly developed by the Austrian
Railway Corporation (ÖBB) and Allgemeine Baugesellschaft –
A. Porr AG. Since 1995 it has been the obligatory system in
Austria and since 2001 it has also been used in the construction
of bridges and tunnels in Germany. No problems have
occurred on the tracks already in operation, covering a distance
of approximately 100 km. The oldest section has been
in operation for 17 years without maintenance and service
costs.
TRACK BASE PLATE (TP)
CONSTRUCTION
The principal element of this system is the elastically supported
track base plate. The track-base-plate-system ÖBB–PORR is
based on a 5,16 m long pre-fabricated reinforced concrete
plate with untensioned reinforcement. Thus eight pairs of
supporting points type Vossloh 300-1 are integrated at intervals
of 65 cm. The sole of the plate as well as the tapered
grouting openings are provided with an elastic layer for
decoupling. This results in a reduction in the vibrations emitted
into the foundation (damping of structure-borne noise).
The system weighs 1 t per linear meter and is therefore a light
mass-spring-system.
PRODUCTION, STORAGE AND TRANSPORT
Production is made in a prefabrication plant and/or a field
plant and is therefore independent of weather conditions. Due
to a complete quality assurance system a constant high quality
is guaranteed and documented. The used steel formworks
are adjustable and so they completely cover all radii ranges.
Reductions, block outs, coverings, dowels etc. can be foreseen
with millimetre accuracy using adequate layers. Due to
the “just-in-time-principle” storage place is as a rule provided
in the company plant only. From there the track base plates
are normally transported to their destination by wagon. The
5 t heavy plates are fastened using a special traverse grabbing
into the grouting opening. Each of the track base plate
types is unmistakably marked with a corresponding bar code
set in concrete and can therefore be easily identified at any
time if intermediate storage is necessary. The unloading is
handled with the necessary unloading equipment (portal
crane or lorry with crane) or with any other lifting device if
intermediate storage is essential.
Production of track base plates in prefabrication plant
TRACK BASE PLATE SYSTEM ÖBB–PORR
Length 5,16 m (2,56 up to 5,16m)
Width 2,40 m (2,10 up to 2,40m)
Depth 16 cm (16 / 24 cm)
Openings 91 x 64 cm (top)
87 x 60 cm (bottom)
Weight: 50,00 KN (gross)
51,40 KN (using Vossloh 300-1)
Types: Linear (R>3697 m)
Radii (R=200 up to 3697m)
Railway/suburban railway/underground
Rail: 60E1 (E2) / S54 / S48U
Optional intermediate storage of track base plates
2

SLAB TRACK, SYSTEM
“TRACK BASE PLATE ÖBB–PORR”
ASSEMBLING
The slab track system ÖBB–PORR elastically supported track
base plate, is built on a solid or low-subsidence base structure
such as, for example, a tunnel invert, bridge construction
or hydraulically bond base layer on mass spring systems. As
a rule, the grouting thickness is > 8 cm and therefore the substructure
height up to the upper edge of the track is 60 E1
(E2) > 47,3 cm. Through the tapered grouting openings a
positive locking compound of the track base plate and the
concrete joint sealing compound is achieved.
240
160 80
≥80
60E1(E2)
elastic layer
elastic
track bed
earth connection
2.400
640
concrete joint
sealing compound
reinforcement
concrete joint sealing
compound opening
5.200
track supporting component
650 650 650 650 650 650 650
Slab track system ÖBB–PORR – cross section + top view
If a modified concrete joint sealing compound without reinforcement
is used (> 4 cm), a construction height of > 43,3 cm
60 E1 (E2) can be achieved if necessary. This ensures the
essential flexibility, for example, to optimise cross sections of
tunnels and bridges or to realise track lowering in order to
obtain a bigger cross section (clearance) in already existing
old tunnels (for example Arlbergtunnel and Tauerntunnel).
Unlike sleeper systems, track base plates can provide big
block outs, for example for revision and bearing shafts wherever
needed. Block outs of 1,80 m x 0,80 m have already
been utilized in the tunnel of the north-south-connection in
Berlin. By reduction of the track base plates, cable crossings
of 250 mm width can be planned.
640
upper edge of
the track 0.00
rough clean surface -- invert concrete
920
393
≥473
elastic
layer
concrete subbase
tubbing segment
track base plate
concrete joint
sealing
compound
8 16 23
50 1.800
50
30 1.800
30
2 2
chequer plate 7/9 zinc-dipped
upper edge of
the track 0.00
18 18
-1.32
block out
1800/700
drainage piping
Block out in track base plate for pump shaft – longitudinal section
BASIS FOR MEASUREMENTS AND SPECIFICATIONS
ACCORDING TO EUROCODE (EC)
Vertical loads
Freight train UIC 71
Heavy load train SW 0 acc. UIC 776-1E
Speed v = 250 km/h (A) respectively v = 330 km/h
Axle weight P max stat. = 250 kN at v = 120 km/h
Wear out per support point:
Q dyn = 125 x 1,67 x 1,25 = 261 kN
Horizontal loads
Side shock H = 100kN, but horizontal force in
a mounting axle H = 60 kN; effects of starting
and braking
Reinforcement
Proportion of steel approximately 6 % - mild
steel 550, in case of mild steel 500 appropriately
higher
Quality of concrete
Track base plates
C 30/37 / XC3 / XF3 / XA1L / GK 16 / F 52
Concrete joint sealing
compound > 8 cm
C 25/30 / XC3 / XF3 / XA1L / GK 8 / F 73 (scc)
C 25/30 / XC3 / XF3 / XA1L / GK 16 / F 73 (scc)
Concrete joint sealing
compound > 4 cm
C 55/67 / XC3 / XF1 / XA1L / GK 4 / F 73 (scc)
1.836
Weather conditions
Besides the safe carrying of the loads of the
railway traffic, the absorption of environmental
influences (temperatures) and the discharge of
surface flood water has to be secured reliably
on a long term basis. The track base plates are
connected with each other only by the passing
through tracks enabling a length compensation
within the 40 mm wide joints. Therefore any
deformations caused by temperature cannot
cause any damage. Furthermore the joints can
also be used for drainage.
-1.55
zinc-dipped angle iron
-0.47
incline concrete
3

MODE OF OPERATION
The bedding necessary for the load distribution on the track is
guaranteed by the elasticity of the track mounting. In addition
the elastic rubber granulate layer, amounting to approximately
10 % of the total elasticity, has the effect that high forces are
well distributed and causes a reduction of the stress in the
multi-layered system.
Portal crane
Bedding of the supporting points and track base plates under traffic load
0,00
bedding measured in 6 MP /
calculated according to stress application
-0,50
-1,00
bedding in mm
-1,50
-2,00
-2,50
-3,00
-3,50
-4,00
MP1 MP2 MP3 MP4 MP5 MP6 MP7 MP8 MP9 MP10 MP11 MP12
Laying of track base plates with lorry
PRODUCTION
Laying
free bearing
stressed track
under consideration for plate bedding
Laying of under traffic load
The laying of the track base plates, which have a width of just
2,40 m (2,10 m), is normally done with portal cranes. This
enables the plates to be lifted forwards in the smallest possible
space. In addition, no reloading or intermediate storage is
necessary, because the plates can be taken directly from the
transport wagon. In the case of islands or missing track connection,
the take over and the laying of the track base plates
by lorry with loader arm is the usual practice.
In any case, the track base plates are being laid at the destination
with an accuracy of + 1 cm in order to minimize the
work needed to adjust them.
Adjustment of tracks
After the partial spreading of the tracks positioned at the side,
the work of adjusting the final track begins by using a M36-
spindle. This method guarantees precise track set accuracy in
setting the track requiring no further correction.
Adjustment work is further reduced by an adequate track
geometry of the track base plates. Therefore the time involved
for the adjustment is reduced by up to 50 % in comparison to
other slab track systems.
4

Concrete pumps up to 500 m
DAMAGE CONCEPT
Concrete
Measurement of track positioning with track measurement wagon
A further advantage of the elastic layer is its separation from
the concrete. Therefore the two tapered grouting openings,
which prevent a lift off of the track base plate, can be cut free
or chiselled out and the track base plates can be replaced
separately within three to four hours.
According to the space available, the concrete joint sealing
compound is applied either directly or through a hose pump
up to a maximum of 500 m. The use of a self-compacting concrete
joint sealing compound enables a holohedral embedding
of the track base plate. As a result of the vibration-free concreting
process (without vibrator), the fine-tuning of the track unit
is not affected. Furthermore, it is possible for these slab tracks
to be installed in a short railway block (example: East-West-
Connection Berlin 2002) due to the fast setting process of the
scc-concrete. The concrete joint sealing compound is adequately
reinforced in order to limit wide cracks.
Cut out – top view + longitudinal section
Concreting of track base plate with scc (self compacting concrete)
Lifting – top view – longitudinal section
5

Concreting of refurbishment-track base plate – top view + longitudinal view
BASE STRUCTURES
TUNNEL FLOOR
Tunnel floors have normally no or little subsidence and
they are therefore an ideal base structure for slab tracks.
The slab track system ÖBB–PORR elastically supported
track base plate can be directly mounted onto the tunnel
floor. For surface dewatering every 50 m, or in the portal
areas every 25 m, semi-troughs are put diagonally into the
concrete joint sealing compound. The remaining spaces
up to the top layer of the concrete are usually filled with
gravel or concrete.
Slab track in shield section
BRIDGE
Bridge girder systems can, like tunnel floors, be used as a
direct base structure for the slab track. The horizontal pressure
is transferred within a narrow radius into the bridge construction
by the use of concrete blocks. In Austria it is refrained from
the labour-intensive application of concrete blocks.
1,5%
Noise absober track
Track base plate “ÖBB-PORR”
Concrete joint sealing comound
Elastomer structure
Supporting structure
Balast
2%
Ballast
Concrete blocks
Track axle
Bridge axle
Track axle
Tunnel axis
Bridge with slab track on Elastomer mat – sectional view
1.600 1.700
1.520
3.300
1.680
86.0 66.0 1.730 1.570
74.0 94.0
45.5 32.5
78.0
Ballsting
Track base plate
SOK ±0.00
Concrete joint se al ing compound
+0,18
-0.60
Shield section – Sectional view
Berlin – Main station – Lehrter railway bridges with slab track
6

Essential differences occur due to the rather high deformation,
by disfigurement or shrinkage, caused by temperature
differences, subsidence, or traffic loads as well as creep and
shrinkage. Especially at the bridge joints deformations can
cause unacceptably high track tension and lifting of track supporting
points. In such cases special track-crossing constructions
are necessary in order to reduce deformations to an
acceptable extent. For example, on the 25 bridge girder systems
of the east-west-connections, a total of 50 special trackcrossing
constructions were built, and twelve joining areas
were directly built over with slab tracks (on extensive sliding
bearings).
Track 60E1(E2)
Track base plate
A
Longitudinal member
Track base plate
Cross member
EARTH STRUCTURE
The laying of earth structures is done on a load distribution
plate or a hydraulically bond supporting layer. Based on the
high degree of prefabrication of the track base plates and the
relatively small grouting openings, quality influences due to
weather conditions are kept fairly low. This also applies to
mounting on bridge constructions.
Rail axle
Partial
drainage pipe
made of concrete
DN 200 drainage material
ballast
Absorbing plates
Track axle
Concrete joint
sealing
comound
Upper edge
of track
± 0,00
Bitumen cating
Balast,
granulate 1
washed
2:3
49
6%
Steel concrete distribution
plate d = 30 cm
-0.80
20 2.40 20
Soil exchange
Bitumen cating
WU concrete (C25/30)
Elastically supported
track base plate
210 210
A
Open section – cross section
Section A-A
Track 60E1(E2)
Steel wedge
Concrete
49
Bearing
4x longitudinal member
Cross member
Bearing
79.2 70.6 79.2
Track crossing construction – longitudinal section + cross section
Track crossing construction (track support structure)
Slab track – Open section
7

MASS SPRING SYSTEMS
In case of increased demands on protection against structureborne
noise, the system can be layered on a mass spring
trough (example: cross section mass spring system in tunnel)
or in case of lower construction heights, directly on the extensive
elastomer support (example: cross section mass spring
system on bridge).
The possibility of making block outs in any part of the track
base plate, enables a space-saving positioning of the bearing
shafts in the track axle.
Elastomer mat
Elastomer mat
Track axle
Concentric noise absorber
Track base plate
Concrete joint sealing compound
Elastomer mat
Supporting
structure
Concrete block
Noise absorber at the
edges
Balast
2%
Slab track on extensive elastomer bearing (mass
spring system without trough) – sectional view
Due to the low height of the system (> 47,3 cm), mass spring
systems without troughs can be produced for low construction
heights, for example 25 Hz on approximately 50 cm. On
the bridges of the main station Lehrter Bahnhof, a softer elastomer
was applied in the centre of the concrete blocks area,
unlike in the side areas, in order to avoid punching.
Bearing shaft with bearings when lifting the mass trough
Rail 60E1 (E2)
Steel concrete mass trough
elastic singel bearings
Slab track in shield section – cross section
Application of elastomer
8

ADAPTATION OF ADDITIONAL EQUIPMENT
The track base plates provide a prefabricated bearing surface
with millimetre accuracy, for example, in order to absorb the
noise of traffic and railway crossings. Therefore, dowels with
millimetre accuracy, can be used, for example, for guard rails,
ADAPTATION OF ADDITIONAL EQUIPMENT
blockages, track magnets and conductor rails. In areas of frequency
control, the reinforcement can be insulated against
outside influences.
Noise absorber
Section A-A
Track magnet
Thread rod
Adapter plate
Guard rail
Anchorage device
Base plate
Compensating plate
Elastomer base plate
Elastomer
base plate
Section B-B
Blockage
Conductor rail support REHAU
height adjustable
Adapter plate
Elastomer base plate
Compensation plate
Adapter plate
Compensation plate
Elastomer base plate
Section C-C
Coated reinforcement
for example using AGROVAN 209
C
C
B B
A A
Additional equipment of the track slab system ÖBB-PORR – sectional view + top view
9

TRANSITION FROM BALLAST TO SLAB
TRACK
Transition from ballast to slab track system, “track base plate
ÖBB–PORR”, is carried out according to the standard catalogue
for building slab tracks (4th edition) or in accordance
TRANSITION FROM BALLAST TO SLAB
TRACK
with the ÖBB regulation RZ no. 17220. The ballast area is
solidified by the use of a well-tried procedure with synthetic
resin.
Österreich RZ 17220
Section A-A
65 65
Section B-B
60 ca. 60
ca. 30
60
6.5
Track base plate
Concrete joint sealing compound
24.5
Concrete subbase
Hydralically
bond foundation
Hydralically
bond foundation
Upper edge
of foundation
Upper edge
of foundation
Elastic bond ballast
Slabtrack
Ballast
Slabtrack (FF)
Track base plate
Slab Track with
prestressed-concrete sleepers
Number of sleepers 2,4 m long
8 straight
16 bent
Ballast
15 reinforced concrete sleepers
2,60 m long
15m
20 Stk. Point concrete sleepers
12.00 m
Ballast with
standard sleepers
Trackform 60E1(E2)
60
Tuxiliary track: track form 60E1(E2)
60
60
2.800
2.400
A
A
B
B
65
65
60
60
Elastically bonded ballast 30.00 m - 35.00 m
Full bonding 2.60 m wide approx
0,15 m deep 7.2 m
Partial bonding: (1) rail foot 0.7-0.8 m wide, 0.15 m deep
2. Every second space 0.15 m deep
≥22.8 m
Surface bonding includes strip along sleeper ends, 0.2-0.3 m wide and 0.2-0.3 m deep
30.00 m - 35.00 m
Transition area slab track / ballast (Germany) – longitudinal section, top view + sectional view
10

REFERENCES
Finally, the ÖBB–PORR slab track system, is impressive
because of the visible concrete quality of the prefabricated
REFERENCES
parts and because its application has now been maintenancefree
for over 17 years.
PROJECT YEAR SPECIFIC FEATURES TRACK LENGTH
Langenlebern 1989 Test track in the field 264 m
Tauerntunnel 1992 Tunnel refurbishment track 2 2.629 m
Helwagbrücke 1993 New bridge construction 52 m
Galgenbergtunnel 1996/1997 New tunnel construction, light mass spring system, bridge 11.040 m
Römerbergtunnel 1997 New tunnel construction, light and medium mass spring system 638 m
Zammertunnel 1998/1999 New tunnel construction, light and medium mass spring system 4.477 m
Kaponigtunnel 1999 New tunnel construction and bridge, light mass spring system 11.170 m
By-pass Melk 1999/2000 Wachbergtunnel, Melker tunnel, bridge 9.042 m
and field, light mass spring system
Wolfsgrubentunnel/Arlbergtunnel 1999/2000 New tunnel construction, medium mass spring system 3.730 m
Siebergtunnel 2000/2001 New tunnel construction 12.902 m
S7-Rennweg Airport 2001/2002 New tunnel construction, medium mass spring system 3.250 m
Blisadonatunnel 2002 New tunnel construction 4.865 m
Tauerntunnel 2002/2003 Tunnel refurbishment track 1 + 2 9.880 m
Unterwaldertunnel 2003 New tunnel construction 2.480 m
Junction Rohr 2003 New tunnel construction 1.691 m
Junction Wagram 2003 New tunnel construction 2.870 m
Lehrter Bahnhof 2001/2002 Bridges/light mass spring system track base plate on 4.690 m
(east-west-connection)
slide bearings 50 joint crossing constructions
Lehrter Bahnhof 2002/2006 New tunnel construction / light, medium and heavy 8.944 m
(north-south connection)
and heavy mass spring system / big block outs
Birgl- and Kennlachtunnel 2004 New tunnel construction and light mass spring system 2.650 m
Pistentunnel S7 2005 New tunnel construction, medium and heavy mass spring system 1.412 m
Lainzer Tunnel 2006/2007 under construction 4.550 m
Arlbergtunnel 2007/2009 under construction 20.812 m
TOTAL
124.038 m
11

ABAP Ref. 317B / 02.07 / 0,25 M Fotos: PORR-Archiv
PORR TECHNOBAU UND UMWELT AG
A-1103 Vienna, Absberggasse 47
Tel. 0043 (0)50 626-1509 | Fax 0043 (0)50 626-1651
www.porr.at | bahnbau@porr.at
The reference brochures of the PORR Group (from ABAP Nr. 217 on) can be downloaded from www.porr.at