Research On Flexural Rigidity And Tension Ientification Of Short Cable

The state of the cable tension is the basis of the important evidence of bridges in arch bridge and cable-stayed bridge. Got the accurate tension of cable is the prerequisite of ensuring the function of structure and extending the useful life of bridges.There are kinds of method for tension identification, but none of them performs well enough, the further research is necessarily needed to improve the measuring precision.Several commonly used measuring methods are summarized and compared in this paper. The main existing problems by analyzing current researches on the vibration methods of cable tension surveying are presented. Then the basic equation for free vibration of cable has been developed and resolved, the basic principle of finite element methods and element vibration equation are discussed. And through finite element analysis, the effects of flexural rigidity and boundary condition on cable tension are discussed. After that, Based on Fuchunjiang No.2 Bridge in Tonglu and Kangqiao Road Bridge in Hangzhou, the tension measuring of short hanger and short cable are studied in this paper.Utilizing the sensitivity of natural frequency of short hanger to additional mass, AMM was proposed for the short hanger tension identification of half-through and through arch bridge. Besides testing the natural frequency in the basic state, another natural frequency in the state of strapping a small mass in a certain section should also get tested. The identification condition is enhanced as two transcendental equations of tension and flexural rigidity are coupled. The nonlinear relationship between natural frequency of hanger and tension or flexural rigidity is refined by applying ANN and GA. Its validity and feasibility are proved by numerical simulation and field tests. The method is applied in the cable force measurement of the Fuchunjiang No.2 Bridge in Tonglu at completion stage.Based on KangqiaoRoad Bridge. Hangzhou, the boundary constraint method is proposed to identify the short hanger tension of partially cable-stayed bridge by making the effective length and the boundary condition to be known. Field experiments was taken to prove this method to be validated in tension identification of partially cable-stayed bridge, and also be feasible in engineering. The method is applied in the cable force measurement of the KangqiaoRoad Bridge at completion stage to guarantee the bridge safety.