Seismic Researches On Rubber Base Isolated Masonry Structure With Frictional Damper

This paper studies seismic, response reduction of the concrete small hollow block masonry structure with high frictional damper isolation bearings. This researches are carried out with the support of natural science fund of Shanxi province(20051053) and scientific research item of Taiyuan city(200534).In this paper, It is introduced the studies and applications of masonry structure and base isolated technique, the design thought and the analytical mathods of base isolated structure. In order to analyse distribution of horizontal seismic shear force in walls, this paper analyses a six- storey masonry structure under 8 earthquake fortification intensity by finity element method together with simplified method issued by seismic design code. Researches show that results of simplified method have significant error in some case, especially error in upper floors walls is larger than that in lower floors walls, so this paper computes earthquake response by finity element method the following text.Based on FEM theory, In order to research the status of masonry structure, under 8 earthquake fortification intensity, this paper analyses dynamic time-history method of one six-storey masonry structure with rubber restoring force and frictional damper and without isolation, compares seismic bearing capacity of walls between isolation and without isolation.The frictional bearing is modeled by node to surface contact Contac49, it is better to imitate friction. The restoring force model of rubber bearing in this paper is adopted bilinear model, the vertical force-deform is adopted linear elastic model, so the mechanics model of rubber bearing is established by two elements: horizontal direction is adopted Combin40 spring element imitated and vertical direction is adopted Combin14 element.Study in this paper shows that when using friction damp rubber isolation, Shear between layers,displacement between layers and the acceleration are less than without isolation and the remnant displacement with rarely occurred earthquake is less. the compare with six-storey masonry structure base-isolation and without isolation shows that the biggest horizontal shear ratio is 50%, the reduced earthquake coefficient is less than 0.71.Whether building isolation used or not, it depends on its technical economy. Based on comparing the masonry structure with frictional rubber isolation and the structure without isolation. the analytic results shows the former has better quake-proof nature and add a little economy than the latter.Based on the former study, this paper analyzes the seven-storey masonary structure. Based on comparing the seven-storey structure with frictional rubber isolation and without isolation. the analytic results show the shear between layers,displacement between layers and the acceleration are less than the latter. Seismic bearing capacity of walls of the structure without isolation can't reach the request of earthquake response, the ones with isolation can reach the request.