Research On Mechanical Behavior Of Self-anchored Suspension Bridge With Multi-tower

Relatively mature and perfect research has been done on earth-anchoredsuspension bridges and a serious of related analytical theories and methodshave been formed. In these years, scholars at home and abroad have also donea great deal of study on ordinary self-anchored suspension bridges with singletower or double towers and gained lots of useful results. However, there are nocomparatively systematic rules and technical criterions about self-anchoredsuspension bridges. With the emergence of several multi-tower suspensionbridges, related research has also been carried out, which is mainly forearth-anchored suspension bridges. But the research on the new structure ofself-anchored suspension bridges with multi-tower is rare. Theoretical andpractical knowledge about it is still not comprehensive and deep enough.Therefore, it is of great significance to study its mechanical property. In thethesis, model test, analytical method and FEM are used in the research on themechanical behavior of self-anchored suspension bridges with multi-tower.The main contents of this dissertation are discribed as follows:1. Based on the deflection theory and the features of self-anchoredsuspension bridges with multi-tower. When we establish the equilibriumdifferential equations and deformation compatibility equations ofself-anchored suspension bridges with multi-tower, the longitudinal stiffnessof main tower and Beam-Column effect of the stiffening girder are considered.2. According to substitutional beam method, practical formulas are gainedfor the structure force and deformation of self-anchored suspension bridgeswith multi-tower. The calculation procedure of deflection theory analyticalmethod and the program have been clarified. The accuracy of analyticalmethods and the program are verified by some examples. The program is veryexplicit and the approximate results can be obtained by inputing designparameters. It’s very fit for the primary design and parameters analysis ofself-anchored suspension bridges with multi-tower. 3. A model test has been done about Luozhou bridge in Fuzhou which is inprogress. And it is a self-anchored suspension bridge with three towers. We dothis test in order to investigate the mechanical behaviour of it. The testmeasured values and FEM results are compared to verify the correctness offinite element analysis and testing.4. Use the program of deflection theory and ANSYS program to study theeffect of main structural parameters on mechanical property of self-anchoredsuspension bridges with multi-tower. The results show that the structuralparameters of rise-span ratio, ratio of side span to center span, stiffness andarch of the stiffening girder, longitudinal stiffness of main tower and stiffnessof cable have different effect on its load property, of which the rise-span ratioand longitudinal stiffness of main tower have significantly effect on thestructural stiffness.5. Based on FEM, some research have been done on different restrictionschemes of main saddle and stiffening girder, and whether there exists theconstitution of outside stretching span of self-anchored suspension bridgeswith multi-tower. Comparisons have been made between self-anchoredsuspension bridges with multi-tower, earth-anchored suspension bridges withmulti-tower and self-anchored suspension bridge with double towers. Someadvices on choosing system of self-anchored bridges with multi-tower aregiven according to the analysis.