Analysis of load test on composite I-girder bridge
This paper showcases the importance of field testing in efforts to deal with the deteriorating infrastructure. It shows that when tested, bridges do not necessarily behave as expected under load, particularly with respect to boundary conditions. This is demonstrated via a load test performed on a healthy but ageing composite reinforced concrete bridge in Exeter, UK. The bridge girders were instrumented with strain transducers and static strains were recorded while a four-axle, 32 tonne lorry remained stationary in a single lane. Subsequently, a 3-D finite element model of the bridge was developed and calibrated based on the field test data. The bridge deck was originally designed as simply supported, however, it is shown (from the field test and calibrated model) that the support conditions were no longer behaving as pin-roller which affects the load distribution characteristics of the superstructure. Transverse load distribution factors (DFs) of the bridge deck structure were studied for different boundary conditions. The DFs obtained from analysis were compared with DFs provided in Design Manual for Roads and Bridges (DMRB) Standard Specification. Having observed in the load test that the ends of the deck appeared to be experiencing some rotational restraint, a parametric study was carried out to calculate mid-span bending moment (under DMRB assessment loading) for varying levels of restraint at the end of the deck.
KeywordsBridge field testing Strain measurements Load distribution factors FE modelling Bridge assessment
This research project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska—Curie Grant Agreement No. 642453. The authors would like to acknowledge the Devon County Council, in particular, Mark Colville for facilitating the field test. Additionally, the authors also wish to thank undergraduate student Nick Trump for his assistance during the field test and data analysis.
- 2.Das P (1997) Safety of bridges. Telford, LondonGoogle Scholar
- 5.Puurula A, Enochsson O, Sas G, Blanksvärd T, Ohlsson U, Bernspång L, Täljsten B, Carolin A, Paulsson B, Elfgren L (2015) Assessment of the strengthening of an RC railway bridge with CFRP utilizing a full-scale failure test and finite-element analysis. J Struct Eng 141(1):D4014008CrossRefGoogle Scholar
- 6.ANSYS (2015) Academic Research, Release 16.0, ANSYS Mechanical User's Guide. Ansys IncGoogle Scholar
- 9.Highways Agency (2000) Design manual for roads and bridges. Stationery Office, LondonGoogle Scholar
- 10.Page J (1976) Report 722: Dynamic wheel load measurements on motorway bridges. Transport and Road Research LaboratoryGoogle Scholar
- 11.Glover MH (1983) Supplementary Report 770: Results from the Hull axle weight survey. Transport and Road Research LaboratoryGoogle Scholar
- 12.Glover MH, Shane BA (1983) Supplementary Report 787: Results from axle weight surveys at Lichfield and Barham. Transport and Road Research LaboratoryGoogle Scholar
- 13.Dawe P (2003) Research perspectives. Thomas Telford, LondonGoogle Scholar