Study And Design On Slef-Anchored Deck Arch Bridge

Self-anchored deck arch bridge is a style of deck arch bridge whose special pre-stressed tendon in superstructure can resist the lopsided thrust produced by the different bridge spans. It can be used in the soft ground because of its coarse demand for foundation. Up to now, the study and design on self-anchored bridge is concentrated on the self-anchored half-through, through arch bridge and suspension bridge. There is little systemic and theoretical study about the self-anchored deck arch bridge. So three aspects about the internal force characteristic, the influence factors of self-anchored performance and the method of pre-stressed tendons arrangement are discussed mainly in this paper. The main contents are as follows:Firstly, the plane calculation model often is adopted to design and analyze the arch bridge because of its simplicity. In this paper, Sanshan Bridge, a three-span continues self-anchored deck arch bridge, is taken as example and the results of plane model is compared with that of spatial model for study on the plane model simplified rationality. And the design is also verified with the test results obtained by stress sensors. At the same time, the cases of construction are simulated and analyzed by spatial and plane model for studying the static characteristic of the self-anchored deck arch bridge. The conclusion and fruit might be referred in the future.Secondly, the function of the self-anchored pre-stressed tendons is to balance the lopsided thrust produced by the different bridge spans. Because of its special function, the method of self-anchored pre-stressed tendons arrangement should differ from the other pre-stressed tendon. Based on the study above, two methods of the tendons arrangements are proposed, i.e.,'Firstly Satisfying Demand of Stress and Displacement', and'Firstly Satisfying the Net Thrust in Spring'.Thirdly, the optimal study of the self-anchored pres-stressed tendons is studied by optimal study method. Then, the two optimal methods are proposed, i.e.,'Linear Programming'and'Optimization Method of Improved Genetic Algorithm'is used to optimize pre-stressed tendon arrangement of self-anchored arch bridge, and verified with the project of Sanshan Bridge.Lastly, there are many influence factors of self-anchored performance. In this paper, take Sanshan Bridge as an example, the effect of self-anchored pre-stressed tendon, the time about the full framing removed, the tendon's tension time and the rise-span ratio are chosen and studied. The rational principle method of the pre-stressed arrangements is presented, the proper time about the full framing removed and tendon's tension, and rise-span ratio is proposed.Based on the above, some design and construction advice is presented in the paper. The conclusion and fruit might be referred for making the regulation of self-anchored deck arch bridge, and it is also the basis for the application and spreading on this kind of bridge.