Fatigue Life Assessment of Integral Concrete Bridges with H Cross-Section Steel Piles Mounted in Water

The main aim of the present research is to predict the fatigue life of H cross-section steel piles of an integral concrete bridge that is mounted in the sea. To achieve this purpose, the geometric model of the bridge with a 90 m length including 42 numbers of steel piles was designed using CATIA software. Next, two different stress analyses including static analysis (in order to study the effect of motionless water) and transient dynamic analysis (in order to study the effect of sea waves clash) were performed for extracting the total deformation on the top part of the piles. The finite element results indicated that motionless water has no significant effect on the mechanical behavior of the bridge piles. But the sea waves clash with the piles caused a deformation on the piles. Eventually, the fatigue life of the H cross-section steel pile subjected to the sea waves clash was predicted using two different techniques (finite element simulation and probabilistic approach). The results reveal that the motionless water has no ability to cause fatigue damage to the different parts of an integral concrete bridge. Moreover, it is found that the useful lifetime of steel piles under variable amplitude loading caused by sea waves clash is 39 and 34 years based on the FE and probabilistic analyses, respectively. © 2020, ASM International.