Study On The Effect Of BZ Series Isolation Rubber Bearing On Seismic Performance Of Bridges

With the frequent occurrence of global earthquake disaster,more and more people pay attention to the seismic isolation of bridge structure.At present,"seismic isolation bearing" is the most widely used method in the bridge isolation,which is between the upper part of the structure and the pier set up bearing to change the structure of the cycle and the consumption of seismic energy that reduced the response of seismic force to bridge.For the small and medium span simply supported T beam bridge in the paper that to design a new type of BZ rubber bearing which is simple in structure,unique in isolation performance,low in cost and easy to be replaced.The BZ support is mainly based on ordinary laminated rubber bearing and changed the thickness of the steel plate,the thickness of upper and lower plate,rubber thickness and so on in support to studied mechanical properties of the bearing under the influence of various factors.Finally,thought seismic spectrum analysis method to calculated the seismic response of the structure and have arrived at the isolation effect of the bearing in the medium and small span simple supported beam bridge.The main research contents are as follows:(1)The paper referenced the existing research results at home and abroad,summarized the anti-isolated idea origin of the bridge and the development of various kinds of bearings,the principle of seismic isolation and the research status of laminated rubber bearings at home and abroad.The paper was based on the plain rubber bearing and thought change the relevant parameters that get a new bearing BZ series isolation rubber bearing and to the description of the design principle,working principle,the mechanical parameters of the bearing in detail.Finally,studied mechanical analysis of the bearing performance based on the theory of laminated rubber bearing on the formula.(2)The paper takes a common plate rubber bearing test as an example to carried out the numerical simulation analysis of the bearing and make a comparative study of the experimental results and numerical simulation results to obtain the correctness of the numerical simulation method.The paper is based on finite element analysis software ANSYS 10.0 to established BZ bearing plate rubber bearing entity model and studied the load displacement curves of two kinds of bearings under pure axial compression and compression shear.Comparative analysis of the results that by changed the thickness of the steel plate and rubber layer in the bearing,the BZ bearing has a larger vertical stiffness and a smaller horizontal stiffness.(3)The paper studied the influence of parameters on the mechanical properties of laminated rubber bearings.The paper to establishment of different plate thickness,the thickness of the rubber layer,the section size of a total of 3 sets of 12 bearing model and through numerical simulation to analysis of ultimate shear deformation and vertical compressive stress analysis and summarized the variation of horizontal stiffness and vertical stiffness and made the quantitative analysis of the results that the numerical results provide a reference for the rational the design of laminated rubber bearings.(4)Based on the seismic design codes at home and abroad and calculated the seismic performance of a 2×30m simply supported T beam bridge.The paper studied on the analysis of the bridge in the use of BZ reduced variation of rubber bearing and ordinary bearing case structure vibration and periodic,shear,axial force,bending moment and displacement that get the BZ series of isolation rubber bearing can effectively reduce the bending moment at the bottom of pier support value,and increase the upper structure displacement,safety coefficient of the structure compared to the non-isolation system have been greatly improved that have significant isolation performance in small and medium span bridge.The result can provide powerful guidance for practical engineering application.