Mechanical Properties Analysis And Specimen Design Of Steel Anchor Box With Double Cantilever Cable Girder In Cable-Stayed Bridge Of High Speed Railway

Cable-beam anchor structure is the key part of cable force transfer in cable-stayed bridge.Its structural form,plate stress,performance and mechanism of cable force transfer,ultimate bearing capacity and fatigue resistance are the key points to be understood.The internal steel anchor box of a cable-stayed bridge over Yujiang section of nanjing-Yulin railway is taken as the research background.Now it carries out in-depth research,the main contents and results of the research are as follows:(1)Midas-civil is used to obtain the maximum design cable force value and fatigue stress amplitude of each cable.Considering the structural characteristics,M16 steel anchor box is selected as the test object of the steel anchor box of the bridge.Based on Abaqus finite element software,the von-Mises equivalent stress values,principal stress distribution and shear stress values of the four main force transfer welds of the original bridge model were obtained.According to the shear stress value,the force transmission performance and force transmission mechanism of steel anchor box are obtained.(2)A design method of test specimens was proposed.By comparing the equivalent stress of each plate and the shear stress distribution at the weld of the original bridge model,it was concluded that the test model could be equivalent to the real bridge.At the same time,the rationality and correctness of the design method are verified based on the experimental data of steel anchor box of cable girder of Yongjiang Super large bridge.(3)In order to reduce the number of plates and construction difficulty of steel anchor box with double cantilever cable beam,a simplified design model is proposed.Compared with the original design,it is found that the cable force transfer performance of the simplified model does not decrease,and the stress level decreases,indicating that the simplified model is feasible.(4)720 groups of different models were established based on the simplified model,and the corresponding weld shear stress value and the maximum equivalent stress of the model were obtained.The neural network technology was used to establish the performance prediction model of the built-in double cantilever cable beam steel anchor box,which could provide data reference for the design of the steel anchor box in the future and effectively reduce the workload in the design process of the steel anchor box.