Optimization of the method for calculating influence lines from measurement data

Optimization of the method for calculating influence lines from measurement data As part of the measurement-based reassessment of steel railway bridges, influence lines resulting from the passage of a load vehicle are used to determine structural loading. The commonly used method for deriving influence lines from measurement data is the Braune method, which computes the influence line step by step from the data. This article discusses the matrix method, an alternative method for determining influence lines, and compares it with the Braune method. For this purpose, different factors influencing the result quality of the influence lines were investigated using artificial strain lines generated on the static model of the Norderelbe railway overpass and validated using measurement data obtained during the reassessment of the bridge. The findings demonstrate that the matrix method offers a robust approach to influence line determination and the amount of work involved in determining the influence lines can be reduced in comparison to the Braune method. Furthermore, the matrix method can be flexibly integrated into the existing process of influence line determination.