Zhengzhou Huanghe River Rail Bridge Anchorage Zone By Force Characteristics Of Experimental Research

Zhengzhou Yellow River Rail-Road Bridge is a cable-stayed bridge with continuous steel truss composite girder and six towers on Shijiazhuang-Wuhan passenger express line. The span arrangement is (120+5×168+120) m. The structure of steel anchor box is applied in the anchorage zone of the pylon. This structure has the advantages of clear mechanical behavior and convenient construction. But the structure of the anchorage zone are very complex and bear the giant cable forces. They are the key parts of structural design. In this paper, the cable-pylon anchorage zones of the bridge were analyzed with FEM. The study of segment model test was performed and the mechanical behaviors of cable-pylon anchorage zone were investigated under the maximum designed cable force. The main work has been done as follows:1. The multi-segment anchorage zones in pylon of the actual bridge were analyzed with FEM. The interaction between steel anchor boxes was studied to determine the scope of test model. The test methods were studied to simulate the mechanical behaviors of cable-pylon anchorage zone.2. A large proportion of model with a scale of 1:1.5 was designed and made. Relevant test program was developed. According to the test program, the segment model of the cable-pylon anchorage zone was analyzed with finite element method. The FEM analysis results of test model and the cable-pylon anchorage zone of the real bridge were compared, It showed that the stress level and distribution of the test model and the cable-pylon anchorage zone of the bridge were close, the model test could simulate the mechanical behaviors of the cable-pylon anchorage zone well.3. In segment model test of the cable-pylon anchorage zone, two load cases were completed to simulate the mechanical behaviors of the cable-pylon anchorage zone under the maximum designed cable force. According to the test results, as the load levels increased, the stress of the measuring points increases linearly. The structure worked in elastic behavior. The Mises equivalent stress of each plate in the cable-pylon anchorage zone was less than the material yield strength. The structure was safe and reliable, could meet the strength requirements of design. The model test results and the FEM analysis results were compared, they were close. It showed that test results could further verify the accuracy of the model test results.4. Based on the relevant specifications, the fatigue strength and bearing capacity of ten welding seam in the cable-pylon anchorage zone were calculated. The results showed that the fatigue strength and bearing capacity of the welding seam could meet the requirements of the specifications, and had a large surplus.The production of this paper can provide the basis for the design and the construction of Yellow River Rail-Road Bridge in Zhengzhou and provide references for other model test.