Applied Analysis On Technology Of Seismic Isolation About Long-span Hybrid Arch Type Aqueduct Support Structure In Shanxi Province

With the increasing of the bridge span,the diversification of the bridge type and the light of the structure, the Bridge Technology have a great development. Because of concrete filled steel tube arch bridge has the advantages of light weight, low center of gravity, powerful as a new type of structural system,it is widely applied to the the Aqueduct support structure and others. However, with the bridge span increases, seismic problems is more and more prominent.so the research on seismic damping and isolation of such structure becomes necessary.This paper takes the Yellow River Diversion of the South-to-North Water Transfer Project in Shanxi Yuncheng, the deck hybrid arch bridge of Steel Tube and Concrete Filled Steel Tube was used in the project, based on the similar in support structure between flumes and bridges. Finite element software MIDAS was used to develop the structure of the two model of non-isolation and isolation. According to the unit simulation of the structural components, meanwhile studying the structure’s mechanical properties of their whole on the calculation of the Mechanical model. The main content as follows:Firstly, Finite element software MIDAS was used to establish the whole model of long-span hybrid arch type aqueduct support structure in Shanxi province. According to the characteristics of the lead rubber bearing, adopt non-linear connection unit simulated. The conclusion of the analysis results are also better prove the nonlinear connection unit can be more truly simulate the rigidity, damping and other characteristics of lead rubber bearing, and the effect is satisfactory.Secondly, to analysis self-vibration characteristics of the non-isolation model and the isolation model which have built two models, it has concluded that the structural vibration have three forms of in-plane vibration, Plane vibration and part vibration, and with partial reversing. After using the lead rubber bearing, the cycle of structure prolonged, seismic energy decreases rapidly and improve the dynamic response characteristics of the structure.Thirdly, using the response spectrum and the time-history methods for the long-span hybrid arch type aqueduct support structure, consider the seismic response of structures under uniform excitation,explore the impact of the seismic structure under seismic load combination and triaxial separate seismic action. Obtain and contrast Inner forces and displacement response of the structure. Under triaxial separate seismic load combination, when use the lead rubber bearing, some important components of the superstructure seismic response have a significant decline. This shows that the performance of the lead rubber bearing on damping seismic energy is significant. Under vertical seismic force, seismic damping effect is not obvious.Fourthly, reasonable choice for the lead rubber bearing design parameters, the deformation of some structural elements not only did not increase, but a certain decrease.This shows that the rational optimization of lead rubber bearing design parameters can not only improve the arch feet force, and control the deformation and ensure the normal order of the structure.