The Dynamic Characterics And Earthquake Resistant Analysis Of High Pier-Long Span Continuous Rigid-Framed Bridge

Bridge is a hub for transportation system projects and an important part of lifeline engineering. In the southwest and northwest parts of China, mountain roads and railways, roads across the deep canyons or rivers are often built by using high pier-long span continuous rigid frame bridge. However, these areas are the major distribution areas of earthquakes. If the bridges were damaged, it would be very difficult to restore transport because of the specific terrain environment. What's more, the earthquake relief operations will be severely affected and the losses caused by the secondary disaster of earthquake will be greatly increased. Therefore, it is necessary and significant to carry out a research on earthquake resistant problems of the high pier-long span continuous rigid-framed bridge.In this thesis, with the Laba jin Bridge under construction as a research background, the author makes a systematic analysis of the dynamic response of this bridge by way of the large-scale finite element analysis software ANSYS. The Laba jin Bridge has the following characteristics:1) The main span of the highest pier is up to 182.64m. It is also called the ultra-high pier, currently the highest in Asia;2) The bridge pier has the steel-concrete composite structure, which is a new qualified high pier column structure. Since this structure is first to be used in China, there is neither design specification to refer to nor any experience in engineering to draw upon;3) The curve starts from the bridge longitudinal axis K39+395.67 and the curve radius is 2500m.In view of the above characteristics of the Laba jin Bridge, the thesis carries out a research on it in the following ways:1) To establish a three-dimensional computational model of this bridge, which reflects the stiffness of structure, the specific distribution of quality and the composite performance of concrete filled steel tube laced columns2) To make an analysis of the dynamic characteristics of the bridge in order to know about the overall stiffness of the structure and the stiffness distribution, and to determine the relative weak position3) To make a qualitative analysis of the bridge's earthquake resistant ability, including the analysis of seismic response spectrum, the time-history analysis of dynamic linear, the traveling wave effect and the dynamic nonlinear of geometric nonlinear.4) To sum up the characteristics of the seismic response of the bridge so as to provide a reference for the similar bridge construction and offer some constructive suggestions for the finite element simulation of the high piers made of concrete filled steel tube laced columns.In this thesis, the author has got some seismic response results of Laba jin bridge by using different calculation methods. At last, the author, according to his own experience, points out some problems to be solved in the future research.