Measurement And Analysis Of Global Stress And Local Stress In Cable Girder Anchorage Zone Of Railway PC Low Tower Cable-stayed Bridge

The theory and practice of the Low-pylon Cable-stayed Bridge have achieved unprecedented breakthroughs after almost half a century development,especially the continuous progress of finite element technique based on the numerical calculation,which can further expand the application range of unique architectural beauty.Based on the Jinsha River Bridge in the Miyi to Panzhihua of the Chengdu-Kunming railway,this paper established the finite element model of the bridge both global and local information.We also compared the test data according to structural internal force and stress theoretical data form model calculation,and gave a conclusion on the rationality of the anchor block design.First of all,the paper analyzes the current situation and existing problems of the local stress in the Low-pylon Cable-stayed Bridge and cable-girder anchorage zone,and puts forward the research purpose based on the briefly reviewing and summarizing the research results of the development of the Low-pylon Cable-stayed Bridge.What's more,the bridge integral model was established using the bridge structure finite element analysis software BSAS,and the internal force,stress,strain and force values of the bridge construction and operation stages were calculated.The data of 1/4,3/4 and mid-span section was analyzed,calculation results of BSAS and Midas was compared,and verified the correctness of the internal force and stress calculations.Thirdly,the local stress model of the selected cable girder anchorage zone was established by using ANSYS.The results showed that the main girder and cable-girder anchorage zone were under pressure by the coupling effect of prestress and Inclined cable.There was tensile stress in the part of area by the coupling effect of simulation of prestressed truss element nodes and concrete solid element node.But the coupling effect will not appear in the actual stress.Most of the chamfer zone were also under pressure,and tensile stress generally occurred in the part of a structural mutation.Although the maximum tensile stress exceeded the allowable tensile stress of concrete,it could not cause structural damage because of small distribution.Finally,the test data was arranged and analyzed base on the work plan discussing of stress test in the Jinsha River Bridge,and obtained the conclusion that the theoretical analysis was consistent with the test data through the comparison of the field test data and the numerical calculation results.