Study On Mechanical Characteristics For Segment Of The Anchorage Zone Segment Of Cable-Stayed Bridge Tower

Since the first modern cable-stayed bridge named Stromsund with a span of 186.2m was constructed by Sweden in 1955, the development of cable-stayed bridge has been springing up like mushrooms, showing great tendency. The anchorage zone of cable bent tower, the key aspect of cable-stayed bridge, carries complicated forces. As for cable-stayed bridge with long span, the cross section of the anchorage zone of cable bent tower is constructed in the shape of cell, using pre-stressed concrete as the construction material in order to increase the inertia moment and balance the great tension of inclined cables by exerting horizontal pre-stress. With the development of cable-stayed bridge, the application of annular pre-stress is becoming mature. However, there are still many related skills not having been overcome yet which would be improved further.As for the designing of cable-stayed bridge with long span, nowadays the finite element method is universally applied as an effective way for pre-stress analysis of the anchorage zone; while due to the anchorage zone's carrying complex forces, the pre-stress is concentrated obviously. For the structure of cable-stayed bridge is gradually constructed as well as the influences of other factors such as construction operation and in situ conditions, it is suggested not only to apply the space finite element method for the anchorage zone of important large bridge with strong cable force but also to carry out full scale model tests which is extremely necessary.This paper introduces segmental full scale model test of the anchorage zone of cable bent tower and its result as well as detailed analysis on test result, taking some large cable-stayed bridge as the engineering background. It also makes use of the big-scale spacial finite element system ANSYS to carefully calculate the spacial stress and strain of the segmental anchorage zone of cable bent tower. Three segments of the anchorage zone of cable bent tower and a single segment and model test are chosen for comparison and analysis. In the end, the result of model test is compared with the calculating result by using the finite element method. According to the contrast theory and tests, this paper discusses about the prestress loss of the U-shaped prestress bundle in the anchorage zone of cable bent tower and desired arrangement. Besides, it also explains the degree of stress and strain of the concrete of the anchorage zone of cable bent tower as a result of the function of cables'forces. Meanwhile, the research on cracking load and rupture load of the anchorage zone of cable bent tower is involved in the paper. In consequence some beneficial conclusions and suggestions about the designing of cable-stayed bridges are obtained.