The Research On The Stability And Dynamics Of Isolated Bridge

The traditional method of the bridge design to resist earthquake is "aseismic design". Devastating earthquake had shown the importance to do safe and effective aseismic design for bridges. Depending on the structure itself to resist the earthquake will pay much. The seismic isolation design is a convenient and economical aseismic design method. It changes the dynamical response of the bridges in earthquake through setting the isolator, decrease the input of the energy, and reach the goal of resisting earthquake. However, to set isolator will result in the decrease of bridge's lever displacement restriction, and then reduce the stability of the whole structure. It is all known that the bridge design must satisfy with two ultimate situation, one of them is the bearing capacity ultimate, it involves the stability bearing capacity. Therefore, it has practical significance to this research. Up to the present, we can't find much more research on the isolated bridge structure. In this paper, I will do some calculation to one of the Highway Bridge, using the finite element method, and then open out the infection the isolator done to the whole stability and dynamical characteristic of the bridge. In this paper, some basic theory is expatiated before the example. At first, the aseismic design method and the seismic isolation design method were being discussed and compared; And then the stability and dynamical characteristic were dissertated one by one, including the knowledge about nonlinear finite element; Rubber is a kind of rising engineering material, it is the important segment of the isolator device, so it's characteristic is being detailedly described in this paper. In order to find out the influence the isolator done to the bridge, two model is set up, one don't have isolator and the other do. The huge software ANYSIS is used to set up the entity model of whole bridge (including the isolator). Though calculation, the conclusion following is gained: the stability is better and the dynamics is much weaker without isolator tan with isolators for the bridge. The final purpose of the isolated bridge design is to satisfy the dependability. So we should assure the integer stability in the isolated bridge design, not just consider the isolating effect of the bridge structure.