Stability Of Through Arch Bridge Without Wind Bracing And Security Of Suspenders

With the development of modern materials and construction techniques, the bridges become longer and longer. During the course of the development, arch bridges always act one of leading actors because of their ascendancy of structure.With the span increasing of the arch bridge, the problem of stability becomes more and more important. When the ratio of its span to width is small, the in-plane stability is dominating. However with the ratio increasing, the later stability is more serious than that in plane. Designers want a simple method but exact enough to calculate the load of stabilization for both in-plane and out-plane, especially when the arch lean initially. The constructors think it is necessary to find a standard to measure the effects of construction error to the whole arch structure. For the two aspects, the paper does some things to solve them.Chapter two in the paper introduced the analytic method for calculating for in-plane stability it is suited for arch bridge of all kinds of arch axis. For the circular arch axis, the method in the chapter is simple and accurate. But for other kind of arch axis, it becomes complex, some literatures verified that circular arch substitute others is accurate enough. For the latter stabilization, three typical axis of arch are particularized to calculate their stability, and the effect of stiffness of deck (or tie) can be taken into account. The analytic method in the paper and numerical calculation both proved that the deck's stiffness can help the arch to be more stable. When the arch has initial latter displacement, the arch bridge's stability great reduces, but the deck performs a more important function.Suspender is one of half-through and through bridge the necessary member. Arch bridge develops greatly, but the study of suspender is later relatively. Till a tragedy's alarm happened, researchers attach importance to it. At present, short (stubby) suspender exists many problems to study, such as measuring its force, cauterization and fatigue. The paper takes a advice to measure the force of a suspender by a simple and accurate enough formula. Additionally, the paper specifies the theory of cauterization and fatigue, and gives some advices to protect it.