Structural Analysis And Test To Cable Damage Of Cable-stayed Bridge

Cable-stayed bridge decks are like the elastic supporting continuous beam and the cables are like bridge piers, which all incline towards a bridge tower, then the tower transfers the cable forces to the foundation. Oblique thrust produces horizontal thrust that makes horizontal thrust around the tower self-balanced, forming a self-anchored system; the cables are under great tension and the tower sustain great compression. Therefore, the cable is important force member in cable-stayed bridge. Sudden break of a stayed cable may lead to structure's sudden catastrophic destruction. As time goes by, most cable-stayed bridges will face the same problem that their load capacity decrease because of the cable corrosion, so cable replacement for Cable-Stayed Bridges is inevitable. Some research and study on static and dynamic analysis of cable-stayed bridge cable replacement has certain significance. Taking cable replacement of Jiaopingdo Chinsha River bridge as the engineering background, this paper researches and analyzes the Mechanical Performance of Cable-stayed Bridge through different levels of cable damage and load test after replacing the cables.The results are as follows;1.The paper analyzes the major factors,the phenomenon and cause of cable-stayed bridge cable damage and discusses the influence of cable damage on stress performance of cable-stayed bridge. On the basis of previous scholars'research results, the paper major studies stress performance of cable-stayed bridge cable damage with a three-span concrete cable-stayed bridge with double pylons in Yunan Province.2.To take elastic modulus as a variable of cable damage, using finite element analysis software builds the bridge calculation model and simulates the cable-stayed bridge cable damage. The calculating simulation divided into two cases,which are different cables fracture and diferent damage degree of same cables,anlyzing the trend of main beam linear,cable tension, structure natural frequency and viberation mode of concreate cable-stayed bridge. The paper concludes the influence law from the research, so,it can offer some references for other similar anlysis on stress performance of cable-stayed bridge cable damage.3.JiaoPingdu cable-stayed bridge made an static and dynamic load test after changing cables, by comparing the test results with theoretical data, it anlyzes static and dynamic characteristics of cable-stayed bridge in the test load conditions.The results are as follows:the influence of long cable damage on stress performance is more than short cable. when unilateral cables are fractured, the torsional response effect of short cable fracture is more than long cable.Cable fracture is focus on the changeable vertical bending viberation mode and torsion viberation mode. The structure internal force distributes reasonably in the test load conditions and it meets the operating requirements.