Case Study of a Steel-Soil Composite Bridge - a Critical Reflection of the Finnish Design Guideline
Erhart, Marcia-Mariel (2024)
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2024051311463
https://urn.fi/URN:NBN:fi:amk-2024051311463
Tiivistelmä
Steel-soil composite bridges are commonly used for small to medium span structures and are of increasing interest as they are cheap, sustainable, and easily replaceable. Unfortunately, the design of steel-soil composite bridges is still heavily experience-based rather than being based on mathematical modelling. Internationally, several publications exist providing design manuals and the Finnish Transport Agency (Liikenneviraston) also published the “Teräsputkisillat – suunnitteluohje, 2014-10” guideline.
This study aims to take a closer look at the design criteria provided in the 2014-10 guideline by conducting a case study of a steel-soil composite bridge designed in 1979. The case study compares the theoretical calculations according to the 2014-10 guideline to documented defects on the structure in 2017. The calculations show that while the load bearing capacities were sufficient, the corrosion protection of the bridge designed in 1979 was inadequate, which was confirmed by the corrosion on the structure documented in 2017. The second kind of defect documented is the deflection of the structure. According to the 2014-10 guideline, the deflection should not be a relevant factor in the design and receives no further consideration.
The results show that there needs to be more specific calculations regarding deflection in the 2014-10 guideline to improve the service life of the structure. Further research in the preliminary compaction of cover and surrounding soil could also be of value, as it might improve the soil’s arching behavior.
This study aims to take a closer look at the design criteria provided in the 2014-10 guideline by conducting a case study of a steel-soil composite bridge designed in 1979. The case study compares the theoretical calculations according to the 2014-10 guideline to documented defects on the structure in 2017. The calculations show that while the load bearing capacities were sufficient, the corrosion protection of the bridge designed in 1979 was inadequate, which was confirmed by the corrosion on the structure documented in 2017. The second kind of defect documented is the deflection of the structure. According to the 2014-10 guideline, the deflection should not be a relevant factor in the design and receives no further consideration.
The results show that there needs to be more specific calculations regarding deflection in the 2014-10 guideline to improve the service life of the structure. Further research in the preliminary compaction of cover and surrounding soil could also be of value, as it might improve the soil’s arching behavior.