New Self-anchored Suspension Structure System And Key Technologies

As an ancient bridge type, suspension bridge was widely used and appreciated because of its concise line shape, beautiful visual impression, and specially, its super span. However, suspension bridge is limited under 600m span because of its enormous anchorage and the huge cost. The self-anchored suspension bridge, however, has both better adaptability and better visual impression than ordinary suspension bridges, but does not have the flaw. So, this kind of bridge is widely used recently.Foshan Pingsheng bridge, which is the first self-anchored suspension bridge with single tower, one main span, many side spans and steel-concrete combined section, has the largest span within all the self-anchored suspension bridges built or under construction all over the world. Researches were performed on the designing and construction of the bridge, whose vise main designer was the author. Results achieved in this essay were as follows:1, Systemic investigation was carried out on the structural system and the parameters of the bridge. Appropriate ranges of the parameters were thus achieved and then applied in the designing of the bridge. The result provides good references for the design of the self-anchored suspension bridges to come.2, Theoretical studies were carried out on the static performance and stability of the whole bridge. Meanwhile, a 1/20 scale whole bridge model test was performed which provides a reference for the calculation and capability of the bridge and ensures good agreement between the completed state of the theoretical[ results and the completed state of actual bridge.3, Dynamical responses of Pingsheng bridge, such as responses to wind and seism, were studied. The wind response and safe distance between of the parallel decks and parallel main cables were experimented and the relation between the distance of beams, the diameter of cable, the distance of cables and the wind response of the bridge. Corresponding measures was applied in the bridge to ensure the safety of Pingsheng Bridge. The work provides good references for the bridge design of the same type.4, A steel-concrete combined section was adapted in the steel girder of Pingsheng bridge. Series of researches were carried out on the conformation of the connector, connecting members, the skid resistance and the fatigue resistance of the steel-concrete sections. Researches and experiments have been carried out on the PBL shear key and P-u curve under different conditions was drawn. The results were applied in the design of the connector between steel and concrete sections of Pingsheng Bridge. A 1/4 scale model test were carried out to testify the security and rationality.5, Anchorage system plays the most important role for a self-anchored suspension bridge, and its capability and rationality decides both the distributing of internal forces and the outlook of the bridge. The main cable of Pingsheng Bridge (half of the bridge) carries a horizontal force of 110000kN and a 70000kN of vertical force at the anchorage point of the side span. According to that, investigations on the conformation of the anchorage span, the transferring direction of forces and the capability of the anchorage were presented in this paper. And problems in design and construction of the bridge were thus solved.6, Systemic researches and tests were performed on the construction plans of the steel girder and the hangers according to the special landform and unique structure of the bridge. Jacking erection methods fol the steel girder and step methods using the unstrained length of the cable and plus hangers to erect and adjust the hangers were finally decided. The plans were proved to be appropriate and safe according to the on-site construction of the bridge.