Dead Load Effects Identification Of Cable Supported Bridge Structure Based On The Cable Force Estimation

Cable supported bridges have been widely used for the strong spanning ability, beautiful structure and reasonable force. Cable is an important structure component of cable supported bridge structures, cable force directly affects the stress state of the beam. Accurate measurement of the cable force is the precondition of evaluation of bridge stress state. In addition, the accurance of the parameter affects the precision of the cable force measurement. As long as the cable force of completed bridge state is obtained, the dead load effect of main girder can be accurately identified.In this paper, the research results of cable force measurement and dead load effect identification of scholars in recent years were organized. Analyzed the structure features of the existing cable force approximate calculation formula. Presented the linear model between the square of cable frequency and cable force. Established a finite element model of cable, and test the cable force of Beihuan Bridge in laboratory. Verified the linear model is objective existence. Present the engineering application process of cable force measurement based on the linear model.The problems of linear model in the cable force measurement parameter identification are unresolved. Deduces the identification formula of linear density and flexural rigidity of cable. Presented the method of flexural rigidity identification based on the errors decreased by frequency order. According to the cable finite element model and laboratory test data, validated parameter identification precision and analyze the sources of error. Presented the density and flexural rigidity identification process.Analyzed the disease situation of Beihuan Bridge in Datong. Discussed identification method of dead load effects by measuring the cable force. Through the contrast analysis of dead load effects of continuous beam and cable supported beam, presented the method of dead load effects identification of cable supported bridge. Linear model method of cable force measurement has high precision. Thus, the dead load effects of cable supported bridge can be accurately identified. Established the finite element model of Beihuan Bridge. Assumed the node displacement, simulated the disease state, and forced the cable to make girder to take off the plane. Through the two state under dead load effect contrast, proved the dead load effects can be identified by the measurement of cable force. Solved the influence of the dead load effects under the state of assuming forced displacement on the node, presented the changed value of dead load effects caused by support subsidence.