Study On Static Behavior Of Cable-stayed Bridge Strengthened By External Prestressing

Cable-stayed bridge plays an irreplaceable role in national economy,culture and environment with its unique spatial shape,excellent spanning ability,mellow construction technology and many other advantages.For a long time,the majority of bridge practitioners have focused on how to ensure the safe and stable operation of cable-stayed bridges.Taking a reinforced concrete cable-stayed bridge in China as an example,on the basis of determining the appropriate reinforcement scheme,the sensitivity of the overall and local parameters of the structure is studied,and the static behavior test is carried out to analyze the static performance of the cable-stayed bridge in the actual operation process.The main research contents are as follows:(1)According to the actual construction process of a reinforced concrete cable-stayed bridge in China,the overall finite element analysis model of the bridge is established.The structural calculation,disease mechanism and damage state simulation of the original bridge are analyzed.The common reinforcement methods of the bridge are studied and analyzed.The improvement degree of the bending ultimate bearing capacity and the improvement effect of the vertical displacement are compared and analyzed.The appropriate reinforcement scheme is selected in order to provide certain reference value for the actual engineering reinforcement.(2)According to the above reinforcement scheme,the whole finite element analysis model of the bridge after reinforcement is established.The influence of parameters such as structure weight,structure stiffness,temperature,cable tension and prestressed tension on the mechanical performance of cable-stayed bridge is analyzed.Finally,the main parameters affecting the static behavior of the structure are determined,which can be used for reference for the later operation and maintenance of similar cable-stayed bridges.(3)According to the static behavior test of the supporting project,the vertical displacement of the main beam,the strain of the main beam and the main tower,the deflection of the main tower and the increment of the cable force are the main test elements of the static performance.The measured data and the theoretical calculation data are compared and analyzed,and the actual reinforcement effect is evaluated.