In-operation experimental research on fatigue characteristics of orthotropic deck

Abstract

To research the key problems of the fatigue strength and fatigue performance evaluation of the steel orthotropic bridge deck of the large span suspension bridge, the One Yangtze River bridge is taken as the research object. The experiment model is determined by the finite element analysis of the multi-segment model. During the design life period, four key fatigue vulnerable parts of two full-scale segment steel box girder models are tested. The design life cycle fatigue tests of four key fatigue vulnerable parts use two full-scale segment steel box girder models. The experimental result and theoretical calculation showed that the stress distribution of each fatigue vulnerable detail and its surrounding area is basically consistent with the results of the finite element analysis. The mechanical properties of each fatigue vulnerable detail did not change significantly, and it shows that the fatigue failure of the models has not occurred in the process of 2 million loading cycles. The principal tensile stress of each key measuring point in the test basically changes linearly, and the principal tensile stress has good symmetry in the two processes of loading and unloading. There are significant differences in the fatigue strength of different fatigue vulnerable details, and the fatigue characteristics of structural systems are complex. At the same time, it is proved that the fatigue performance of the orthotropic steel deck of the bridge meets the design requirements, and it has a certain safety reserve.