Full-scale fatigue tests of a cable-to-orthotropic bridge deck connection

Using a specially designed lever arm, full-scale fatigue tests of a cable-to-steel orthotropic bridge deck connection were conducted in the National Center for Research on Earthquake Engineering (NCREE). A 9.59 m long, 2.7 m high and 2.55 m wide full-scale bridge deck was constructed in the steel fabricator's shop. The specimen was then shipped and anchored on the strong floor in NCREE's laboratory. Four actuators were mounted horizontally on the reaction wall and connected to the top end of a steel lever arm. The lever arm was pin-anchored at the bottom end to the strong floor while its one-quarter point was attached to the rear end of the stay-cable anchor box. Two-million cycles of fatigue loads ranging between 3836 and 6759 kN were applied at the rear end of the stay-cable anchor box, and the forces of the fatigue test correspond to design dead load plus the maximum and minimum design live loads in the cable. Tests results confirmed that the full-scale welded cable-to-orthotropic bridge deck connection sustained two-million cycles of the stated loading without any sign of failure. Test results indicate that the strains observed in the test specimen can not be satisfactorily predicted by the FEM analysis with the model used in this study.

► In this study, a unique test setup was designed and constructed.
► The fatigue test of a full scale cable-to-bridge deck connection was conducted.
► The test specimen sustained two-million cycles fatigue loads without any fracture.
► The FEM analysis can not accurately predict the strains in the specimen.