Experimental vibration tests in fatigue evaluation of a riveted truss bridge

Abstract

The paper presents a practical implementation of experimentally supported fatigue life prediction of an 80-year old riveted truss bridge. The bridge is an unique road structure crossing the Vistula River in Puławy in Poland. Its main part is composed of 5 large spans with Gerber beam static system. In the previous decades the bridge played an important role in the transportation system of the whole region and despite of its advanced age and historic value it was intensively exploited by heavy vehicles. Thus, taking into account the age of the structure and intensity of the traffic crossing the bridge in the past, some doubts about the remaining fatigue resistance of bridge critical members − defined by the fatigue safety level and damage indicator − were formulated. Fatigue evaluation of the old riveted truss structure was performed according to general assumptions of the Eurocodes [1, 2] and the European Recommendations for Estimation of Remaining Fatigue Life of Existing Steel Structures [3]. Essential input data used for estimation of fatigue damage accumulation in critical bridge components as well as for prediction of residual lifetime of the whole structure was based on experimental vibration tests performed under real live loads.