Fatigue Test Study of Model for Connection Detail of Integral Deck Structure Subjected to Two-Way Tensioning

The main bridge of Dashengguan Changjiang River Bridge in Nanjing is a six-span continuous steel truss arch bridge and the deck of the bridge makes use of the integral steel deck structure.The full-scale model for the connection detail between the deck and gusset plates of the bottom chord of the main truss is fabricated and the fatigue tests for the model are made in three stages.After the fatigue test in each stage is completed,the upper limit of the test load in that stage is used to continue to make the static load test.The analysis of the ANSYS shows that the design and loading of the model can meet the requirements for simulation and the loading applied in the tests can represent the force conditions of the actual structure.The static load test shows that under the action of different loading levels,the model is still in the state of elasticity and is almost without residual stress after unloading.The results of the fatigue tests further show that when the model was tested under different times of load cycling and the stress redistribution due to the fatigue damage influence does not occur.Under the action of loading according to the given calculated stress amplitude,the life of the model under constant stress amplitude loading is longer than 200×10~4 times of load cycling,the fatigue resistance is greater than the two-way stress amplitude of the designed test load and the connection detail between the deck and gusset plates has sufficient fatigue resistance capacity.