Fatigue Experiment of Prefabricated Orthotropic Steel Deck Applied to Passenger Car Only

Until now, the fatigue experiment of steel deck has been variously performed. However, it can be seen that these experiments are limited to bridges designed with the truck loads of HS-20 and DB-24, and there is no fatigue experiment of steel deck designed with passenger car live loading. The purpose of this paper is to propose a new robust steel deck system and to evaluate its fatigue strength through the reliable experimental tests under the passenger car load. In this research, in order to avoid such inconvenient field welding, two main girders are first installed and the steel deck modules are assembled by bolted connections on the girder. And with considering economical efficiency, the U-ribs are arranged laterally at spacing of 400mm to directly deliver the passenger car load to girders, and the longitudinal beams are set in a large spacing of 1.45 m to mainly brace the U-ribs together. Three specimens were tested with different loads of 79, 106, and 132kN under the loading frequency of about 1.1 Hz. In result, the crack occurred on the welding connection between the U-rib and the longitudinal beam, and continued to grow up onto the U-rib. The fatigue strength at mid-length of the longitudinal beam of the test specimen can be evaluated as Category D based on the KSCE and AASHTO, or Category E on JSSC. The stress range in the proposed prefabricated orthotropic steel deck under service loading well satisfies the desired stress range suggested in KSCE.