Technology On Cable Replacement Of Space-twisting Cable-stayed Bridge

The cable-stayed bridge with its crossover capability comparable to suspension bridge has brought great convenience to the transportation development since its birth. Space-twisting cable-stayed bridges are popular in recent years with its special way of cable arrangement, which differs from the usual way of cable arrangement and gives viewers a visual aesthetic feeling of space. However space-twisting cable-stayed bridge also has problems faced by all cable-stayed bridges: the corrosion damage of cables. Cables as the chief bearing components are of great importance to the bearing capacity and structure security of cable-stayed bridges. But cable-stayed bridges operated for years usually face the problem of cable replacement due to the defects of cable itself and service environment.Space-twisting cable-stayed bridges, as a new kind of cable-stayed bridge, face the inevitable problem of cable replacement after years of operating. Yet there is little research on structural behavior of this new kind of cable-stayed bridge, and more work need to be done about the cable replacement.This paper, based on the analysis of cable replacement of normal cable-stayed bridges, compares cable replacement plans of space-twisting cable-stayed bridges. First some cable arrangements and structural property of cable-stayed bridges are introduced, and cable replacement theory and methods at present are expounded. Second preliminary identifying the cable replacement plans overall considering its own characteristics of cable-stayed bridges. Finally, this paper selected four kinds of cable replacement plan for space-twisting cable-stayed bridges to contrast analysis, and then we know: replacement of four symmetrical cables and cable simultaneously symmetrical replace two alternate cable replacement method, the main beam span which near the seat at the use of the method that at the same time replace the four cables; In the more sensitive of the main girder span displacement of the cable segment, using a symmetrical way to replace the two-for-cable cable; while near the pylon replace the four symmetrical cables at the same time. This staggered cable replacement method,not only have a less impact on the deformation and internal forces in the main beam, but also speed up the construction schedule. Based on the analysis above, this paper recommended to using the fourth method for the cable replacement of space-twisting cable-stayed bridge.