Presented at the XXIV Nordic Concrete Research Symposium in Stockholm, August 17-19, 2022.

1. https://www.linkedin.com/
company/byggkonstruktion
R C Trough bridges over the Kalix RiverRC
Gabriel Sas, Jaime Gonzalez-Libreros,
Chao Wang, Silvia Sarmiento, Lennart Elfgren, LTU
XXIV NCR SYMPOSIUM 2022
1/20

2. 1660 Iron ore
in Northern
Scandinavia
The ore was first transported
To the coast with reindeers
Railway built in 1886 - 1902
Axle load
1888 14 ton
1955 25 ton
1998 30 ton
2020 32,5 ton
2030 35-40 ton?

3. Iron Ore Railway Line
1995
Increase of Axle Loads
from 25 to 30 tons.
What about the bridges ?
Fatigue Capacity ?

4. Lautajokk Bridge had been replaced
with a new bridge, so we brought
the old one into our Laboratory at LTU.
We built a test rig and loaded it in fatigue
Elfgren, L (2015) Fatigue of Concrete Structures,
Research Report, LTU, Structural Engineering.
FULLTEXT02.pdf (diva-portal.se)

5. Load-Deformation Graph
Final static loading after
6 million load cycles.
Deflection, mm mm
Axle Load, kN
New Axle Load 300 kN
2 Mcycles -> No impactkN

6. 2006 Test to Failure of Curved Trough Railway Bridge
www.sustainablebridges.net
A 50 year old bridge was tested to failure in bending, shear shear and torsion
A European Research Project

7. A little more than the design load
Puurula A, Enochsson O, Sas G et al. (2013). Loading to failure and 3D nonlinear FE modelling of a strengthened RC
bridge, Structure and Infrastructure Engineering, September 2013, 1-14 pp
Puurula A, Enochsson O, Sas G, et al. (2015). Assessment of the Strengthening of an RC Railway Bridge with CFRP Utilizing
a Full-Scale Failure Test and Finite-Element Analysis, J. Struct. Engineering, ASCE, 2015, 141, D4014008, 11 pp

8. A train has 68 wagons
each with ca 100 ton ore
12 trains/day transport about
25 Mton/year (increase to 40)
Maintenance cost ~ 45 k€/km, year
Has inspired several EC projects:

9. L U L E Å U N I V E R S I T Y O F T E C H N O L O G Y 9
Trough bridge project
Luleå
Kiruna
Narvik
500 km
126
bridges
119
7
M e a s u r e f a t i g u e a n d
d y n a m i c p e r f o r m a n c e
a s r e a l i s t i c a s p o s s i b l e .

10. Influence of
Increased load on
Fatigue capacity
for f 16 mm bar

11. L U L E Å U N I V E R S I T Y O F T E C H N O L O G Y 11
p

12. Acknowledgements
Many thanks for your kind attention
Gabriel.Sas@ltu.se
Jaime.Gonzalez@ltu.se
Lennart.Elfgren@ltu.se
12 (20)
Swedish Universties of the Built
Environment
(LTH, KTH, Chalmers, LTU, RISE)