The Götaälv Bridge in Gothenburg was instrumented with strain gauges in April 2015. This report is a presentation of the measurements performed until 29 April. The measurements were performed by personnel from the Division of Structural Engineering and Bridges at KTH. The project was commissioned by the City of Gothenburg – Traffic & public transport authority through ÅF Infrastructure AB and performed in collaboration with researchers from the Division of Structural Engineering at Chalmers University of Technology.

The monitoring system comprised 23 strain gauges divided between two areas. One between support 13 and 14 at the South Viaduct and one between support III and IV at the elevated river part. Measurements were performed at four arranged bridge openings and a calibration monitoring using two trucks with known weights. Continuous measurement was also performed during the afternoon Tuesday 28 April.

For the bridge openings, stresses up to 5,6MPa were recorded on the elevated river part. The recorded stresses are lower than those caused by the ordinary traffic in the instrumented locations.

The calibration measurements were performed during night using two trucks with weights of 25,0 tons and 25,1 tons, respectively. Together, they caused maximum recorded stresses of 15,4MPa for the South Viaduct and 16,8MPa for the elevated river part. Associated stress ranges were 19,4MPa and 19,8MPa, respectively. The largest values were recorded in the gauges located close to the mid spans.

Stress range spectra are presented for the short term continuous measurement. The daily traffic gives in general lower stress ranges than the trucks used for the calibration. A large portion of the cycles are distributed over small stress ranges.

For the gauges on the elevated bridge part, the analyses show a significant influence of dynamics on the results.