Study On Anti-Seismic Performance Of Masonry-Concrete Historic Buildings

There are lots of buildings with historical and cultural value in China. These historic buildings are built long ago and are different in structural forms. There is little research on the material properties and structure performance of these historic buildings. In order to afford the historic construction better protection and give guiding suggestions for repair and reinforcement of the historic constructions, it is necessary to study the anti-seismic performance of such buildings.The main research work is as followings:First of all, according to the characteristic of historic buildings in China, based on homogenization theory, and combined with finite element method, in this paper, the representative volume element method was applied to study the material parameters of the wall of historic buildings.Then, the characteristics of the masonry-concrete historic buildings structure was discussed from the aspect of material performance, construction technology and the form of structure. According to the current seismic design theory, earthquake resistance behaviors of two masonry-concrete buildings were analyzed and the weak parts were pointed out.Finally, the finite element models of two masonry-concrete buildings were established, the dynamic properties of structures could be got by the modal analysis. In order to study the anti-seismic behavior of the historic buildings, the method of time-history analysis was used, and the wave of El Centro, Tianjin and Shanghai artificial seismic were all input, the seismic responses of the structures could be got respectively under the case of common earthquake and unusual earthquake.Analysis of two typical masonry-concrete structures show that the dynamic characteristics of the buildings are shown as: the first two modes are translational vibration modal, the third mode is tensional vibration modal. The natural vibration calculated by the finite element modal in this paper is close to the calculation result of that calculated by experience formula. The element model used in this paper to calculate the dynamic characteristics of this structure is reasonable. Compared vibration period and mass participating coefficient considering the effect of mezzanine with that not considering the effect of mezzanine, the conclusion is as follows: the mezzanine decrease the vibration period and increase the structure stiffness; the mezzanine decrease the mass participating coefficient around vertical and make the structure torsion effect decrease. The earthquake action of an internal-frame structure in Tianjin is calculated and found that the result error by base shear method is larger. Through the time-history analysis of two masonry-concrete historic buildings, some conclusions can be drawn: the maximum stress of the wall appears near the doors and windows in the bottom of the building; the maximum inter story displacement appears in the top of the structure.