| With the development of bridge structure design and construction technology,the inclined tower cable-stayed bridge become the landmark of urban bridge design and fully reflect the vitality and vigor of the city as its sleek shape and great tension.Of course,it is one of the preferred bridges in bridge design.But the cable-stayed bridge as a new type of structural composite bridge,its calculation model is directly related to the accuracy and reliability of design,construction,and monitoring.Therefore,it is necessary to study the methods and techniques of finite element modeling.This paper takes the No.2 main bridge of Xi'an Chan Ba Ecological District as an engineering case.Firstly,it builds its calculation model based on full study of modeling methods and techniques.Secondly,it has effects on the statics,dynamics and earthquake resistance of the completed bridge model.Calculate it and compare the results with the measured data of the bridge load test to fully verify the integrity,reliability and accuracy of the calculation model.Finally,using the results of load tests verifies the rationality of the bridge design,the safety and stability of the bridge structure itself.And this paper studies from the following three aspects on the completed bridge model:(1)Contrast and analysis on design proposal of tower-beam elastic connection stiffness parameters,(2)Comparison and analysis on design proposal of main span cable-free side length parameters,(3)Using impact matrix method and comprehensive method to conduct cable force calculation and error analysis.The result provides some reference and guidance for the design and construction of similar bridges.The main work,conclusions and recommendations of the research and discussion in this paper are as follows:(1)Summarize the finite element model method,simulate the structural components and boundary conditions of the bridge,and establish a finite element model.(2)The analysis of static,dynamic and seismic characteristics proves that the established model is reasonable and reliable;the comparison between the measured data of the load test and the calculated results of the model verifies that the model is accurate,the bridge structure itself is safe and stable,that is,the strength and rigidity of the various components of the bridge meet the design requirements;the cable and the structure itself have good cooperative performance,and the overall performance,torsional stiffness and dynamic stiffness of the bridge are good.In addition,the results of seismic analysis indicate that it is recommended to set a limiter transversely to the main tower of the bridge and set the axial force reduction device(i.e.thrust box)for the main beam.(3)The results of comparative analysis of the stiffness parameters of the flexible connections of the tower girder show that its parameter selection of 2.7×10~6 kN/m is relatively reasonable;the comparison analysis of the length parameters of the no-cable zone on the main span side shows that the ratio of no cable length and span of main span between 0.12 and 0.33is more reasonable.(4)On the basis of the calculation and error analysis of the bridge cable forces by the influence matrix method and the synthesis method,it can be concluded that the latter is more effective in the calculation and analysis. |
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