Research Of Design Theory On Concrete Self-anchored Suspension Bridge

As a particular kind of suspension bridge, self-anchored suspension bridge has made an appearance in field of engineering after years dreariness. Preserving shape of traditional suspension bridge, it causes the engineers favor by its elegant and picturesque disorder figure. However, due to complexity of its structure, there are little research data or achievement at home and abroad. This paper has put emphasis on static theory of self-anchored suspension bridge and economical efficiency optimization of concrete self-anchored suspension bridge. The detail as the following:1Research on static behavior of self-anchored suspension bridge by deflection theory. Basal differential equation is derived base on Generalized Great Displacement Variation Principle. It is drawn that basal differential equation based on self-anchored suspension bridge deflection theory is equal to that of earth-anchored suspension bridge based on elasticity theory. Thus it can be concluded that self-anchored suspension bridge is more suit to elasticity theory.2.Detaled design and computational analysis to a middle-span concrete self-anchored suspension bridge in construction- Fu Shun Wan Xin Bridge are done.Contrapose an established concrete self-anchored suspension bridge-Da Lian Jin Wan Bridge, the difference of structure internal force characteristic between concrete self-anchored suspension bridge and earth-anchored suspension bridge. Through computing real projects, mechanics character of concrete self-anchored suspension bridge structure is analyzed. The change laws of internal force caused by transformation of arch degree and rise-span ratio, concrete's shrink and creep are researched. To self-anchored suspension bridge of small and medium-sized span, the internal force of structure is similar to that of earth-anchored suspension bridge except that the axial force of the main beam is on the bigger side. The effect of arch degree, concrete's shrink and creep is distinct. Compared with corresponding horizontal stiffening girder and the computational result without concrete's shrink and creep, the difference is more than 20%. The elastic method is suit to design and computation of self-anchored suspension bridge of small and medium-sized span.3.There are randomicity on material character and geometrical size in structure of concrete self-anchored suspension bridge. This paper analyzed certain geometrical nonlinearity on concrete self-anchored suspension bridge, then did analysis under random static force with Method of Response Surface. At last, aiming at a self-anchored suspension bridge in construction, the structural effect of main beam under vertical load from randomicity of material and geometrical size is computed. Parameter effect on sensitivity was analyzed, and the result shows that random effect of the main beam is the largest. Method of Response Surface is an efficient way. Principal Component Analysis Method is effective on analysis of main variable of nonlinear regression model.4.Based on Method of Response Surface, the optimized model of cost function of concrete self-anchored suspension bridge is established. The author did optimized research on material cost from superstructure of Ji Lin Lan Qi Song Hua River Bridge. Through optimized analysis, a geometrical size of higher comparative quality price ratiocan be found. It is drawn that the most optimized rise-span ratio is about 1/7. It is proved that the design scheme in construction is feasible.