Study On The Mechanical Behavior Of Continuous Steel Truss Bridge Joint With Four-Line Double-Truss

Dongxin Ganjiang River Bridge is a through type continuous steel truss bridge. Its span arrangement is 126+196+126m, which is the first long-span double steel truss bridge with four-line in China. The top chord of the main truss is assembly jointed, which is characterized by great internal force and complicated structure details. Based on the background of Dongxin Ganjiang River Bridge, systematical investigation based on the model test has been done to study the mechanical behavior of A9 joint. The main research contents are as follows:1,In order to get the most possible unfavorable processing conditions of the joints under the combination of dead load and live load, a finite element model is established by the spatial plate shell method according to the characteristics of four-line double-truss plate-truss composite bridges2,The scale model in 1:4 ratio was designed and manufactured in order to simulate the stress states of A9 joint in the position of the middle support of actual Bridge.3,Using the FEM software ANSYS, shell element is applied to simulate joint structure details and local FEM analysis has been done. The joint stress state as well as the performance under the design load and ultimate load have been obtained.4,Scale model test was carried out to investigate the joint stress state and performance under the design load and ultimate load.5,The results of the model test and the theoretical calculation were compared and the validity of theoretical calculation was investigated. The results showed that the stress level of the model test is higher than the theoretical analysis which simulates frictional high-strength bolts by increasing the thickness of joint plates.6,Mechanical performance of the joint under the ultimate load is evaluated through the model test. Furthermore, it is concluded that the design of assembly joint is determined by the stress of joint plate section and rod middle section...