Improving of fatigue assessment method of stud shear connectors using experimental data from studs' test of existing road bridge

Nowadays there are varieties of methods for fatigue assessment of stud shear connectors in bridges with steel-concrete composite superstructures. These methods can consider various parameters, such as traffic flow characteristics, asymmetry factors, etc. Bridge design codes used in Russia are quite conservative in this matter and prescribe fatigue assessment based only on the maximum stress value, taking into consideration the reduction factor, ignoring the actual traffic loads. To improve the methodology for fatigue assessment, the authors of the article performed a full-scale experiment on a reconstructed bridge on the federal highway in Russia. The purpose was to determine the actual dynamic stresses in stud shear connectors from the transport load. During the reconstruction of the bridge, strain gauges were installed on stud shear connectors, and then connected to a digital measuring system. The article provides a complete description of the methods used and the results of the experiment. Based on the obtained data analysis, authors propose recommendations for adjusting the standard impact factors. Based on the results of comparison of the damage values obtained theoretically and experimentally, the authors make a proposal on the need to adjust the design loads used.