Pedestrian Suspension Bridge Applications And Features

With the development of bridges quickly in our country, the application of footbridges also becomes prosperous outstandingly. However in the process of design, people usually consider the safety of its structure and the function, and consider appropriately and do not make a pressing demand for the view and humanities and so on. This directly makes simplification and hipping and scarcity of the style and varieties for the construction of footbridges. Looking up the beauty, economy, environmental protection, application and novel form for footbridges have already been paid attention extensively by the public. With the predominance of the simple structure, beautiful line shape, cheap cost and environmental protection, this kind of old and novel bridge comes into our eyes firstly. Seeing that many people lack the knowledge of stress- ribbon footbridges, the mechanical characteristic and application is analyzed in this paper.1. Started from the developing history, main function and the present state of footbridges in our country firstly, the applied background of the stress- ribbon footbridges has been analyzed and particularity of them introduced. Especially, the fact and theory foundation have been provided for the comprehensive application and anticipation of this bridge in the city.2. By the introduction of theoretical formula, the cable rigidity , flexility, unstressing state, load stress state and the static and dynamic characteristic have been analyzed, and its variable regular and influencing factor have been also discussed.3. Through analyzing example, the relation between axial rigidity and pulling force of the cable and the affection to axial rigidity about gravitation rigidity and elastic stiffness have been discussed. At the same time , dynamical analysis for a given bridge has been done through the software MIDAS, and the relation of between basic frequency and sag ratio of stress- ribbon footbridges and frequency wave on the base of given sag have been educed.The studying result indicates: the first, the application of stress- ribbon footbridges is extensive and feasible, and the foreground is fine; the second, the axial rigidity of cable becomes stronger with pulling force strengthening, and its dominant function will also changes into elastic stiffness gradually; the third, if the span length and the form of cross section are given, basic frequency reduces with the ratio of rise to span increasing, and all less than the average frequency 1.2 Hz of walking. So, human load is not easy to bring the sympathetic vibration of bridges. We can know the structure of stress- ribbon footbridges is also reasonable.