Qr-method For Nonlinear Dynamic Analysis Of Long-span Concrete Filled Steel Tube Arch Bridges

In this paper, firstly, the recent condition and perspective, the types of structures, construction technology, the design method of the fast developing concrete-filled steel tube arch bridge are introduced, and the mechanics performance and uniform theory and the application in practical engineering of CFST. Secondly the author's study are introduced in this paper.The author study mainly the linear static and dynamic, elastic-plastic static and dynamic problems of CFST arc-bridge. Firstly, the author establish the linear static equation on the based of the rigid equation of element by QR-method, and then analysis the inner force of arc bridge, establish the linear dynamic equation and elastic-plastic rigid equation and dynamic equation, then solve respectively the elastic-plastic rigid and dynamic equation by the method of repeated increment and no limit stabilization, arithmetic. Lastly, the author program the relevant computer program by C language, and work out some problems, and analysis one practical engineering problem, at the same time, the author analysis the linear problem of practical engineering under static load and seismic load and the elastic-plastic problem under static load and seismic load. It is compared between the results of QR-method and finite element method, and we can find that the result of QR-method is more precise. This method don't adopt finite element and fluxion principle on theory, so it avoid some enormous and advantages resulted from traditional method. When QR-method is used to analyzing the long-span CFST arch bridges , the result show that this method is not only computed simply but also high accuracy and has better convergence performance, so it is a effective and economic new method.This paper not only has the theories signification but also has the practical value.