Model Design And Experimental Study Of Curved Cable Stayed Bridge

Model test is a common method of studying complex bridge structures,but using the overall model test to study complicated bridge construction stage is very scare.With a small radius curved cable-stayed bridge in Congo taken as the engineering background,the static design and experimental study of the whole bridge model has been carried out.The main contents of this paper include following aspects:(1)The development and characteristics of curved cable-stayed bridge are summarized in this paper,and the research status and similarity principle of bridge model test were introduced,including the similarity relation in the geometric similarity design and that in multiphase material model.(2)Based on the purpose of the model test and the existing practical conditions,a general idea of the model design of curved cable-stayed bridge model test is put forward.Considering the actual conditions of the laboratory,the model scale of 1:20 was determined and the static similarity relation of the model test is derived subsequently.(3)The model bridge is designed based on the principle of stiffness similarity.In order to verify the correctness of the design and static similarity relationship of the model bridge,an ideal model of model bridge is established.The numerical results of the ideal finite element model are compared with the results of the theoretical monitoring revised model of the prototype bridge.The results show that the design of the model bridge based on the principle of stiffness similarity is reasonable,and the internal force of the girder is similar to that of the prototype bridge,and the static similarity relation of the model bridge is derived correctly.(4)Based on the actual conditions of the test site and the laboratory,the components design,counterweight design and the boundary conditions design of the model bridge are completed.According to the characteristics of the model bridge,the finite element analysis of the bridge is conducted by means of using double beam and plate elements to simulate the ?-shape girder being in complex stress condition.(5)According to the purpose of the test,the test conditions,the measuring point arrangement and the test procedures are determined.The device and the method of the cable force adjustment are introduced based on the experimental conditions.To be more specific,the cable force adjustment of the cable stayed model bridge is achieved by a matlab procedure and the relation curve which characterized the tension varied to the length of the cable is obtained by manual measurement.(6)The comparative analysis of the actual test results and theoretical model analysis results shows that the force conditions of the actual structure in the test and that in the theoretical model are basically consistent,which proves that the numerical calculation method for the force analysis of complex spatial stress of curved cable-stayed bridge with ?-shape beam is reliable.