Structure Design Calculate Research About Inclined Pylon Partial Cable-stayed Bridge Without Back-stays

Inclined pylon partial cable-stayed bridge without back-stays has the beautiful figure of the Inclined pylon bridge without back-stays, but its characters of mechanics is more close to partial cable-stayed bridge, and is a new kind bridge type, in recent years, it has been used widely in some city bridges with small span. Upon the base of deep research of inclined pylon partial cable-stayed bridge without back-stays and partial cable-stayed bridge, firstly, this paper reviews the history of development of inclined pylon partial cable-stayed bridge, then, through the balance of still forces theory, the mechanics characteristics of inclined pylon partial cable-stayed bridge is analyzed whether pylon is light and beam is heavy or pylon is heavy and beam is light, combined with the actual project, structure characters about pylon, cable and beam are concluded, at last, designing method and computing content of inclined pylon partial cable-stayed bridge without back-stays are analyzed, and used in actual project.Through these research, it can be drawn the conclusions:1. Inclined pylon partial cable-stayed bridge without back-stays is an inclined pylon and no back-stays structure, and is one kind of partial cable-stayed bridge, the dividing index can use sharing ratio of direct loadΨand stress level of cable [σ], whenΨis less than 30%, [σ] is less than 50 MPa, the inclined pylon and no back-stays structure can be called inclined pylon partial cable-stayed bridge without back-stays.2. The main beam of inclined pylon partial cable-stayed bridge without back-stays has large rigidity and uses multi-span continuum structure model, the span ratio of side and center is less, the prestress concrete can be used; pylon can only incline to the side span, the angle will be close to 30 degree; harp is the main type of cable, the anchor-hold point is at the neutral axle of pylon section, allowed stress is 0.6 time of limit stress.3. The structure analysis of inclined pylon partial cable-stayed bridge without back-stays includes normal structure analysis, stress cross area analysis, construction stress analysis, wind vibration and earthquake analysis and stabilization analysis, five aspects. The normal structure analysis can use beam and diaphragm method.