Shaking table test of masonry structures strengthened with external prefabricated reinforced concrete wall and with added story isolation

In order to research the reinforcement effects on masonry structure strengthened with external prefabricated reinforced concrete wall and investigate the possibility of added story isolation on the top of reinforced masonry structure, the shaking table tests of three 1/4 scaled models were conducted. These three models were reinforced masonry structure model, reinforced masonry structure with added story model and reinforced masonry structure with added story isolation model. The dynamic characteristics and seismic response of models were evaluated under different levels of earthquakes. And then, the models subjected to rare seismic cases were tested again to analyze the dynamic responses of damaged structures. The results indicate that added story isolation structure can prolong the structural vibration periods efficiently and increase the damping ratio. Whiplash effect of superstructure of added story non-isolation structure is very obvious. Added story isolation structure can not only reduce seismic response of the substructure effectively, but also reduce the seismic response of the superstructure; therefore, reinforcement effect and seismic performance of added story isolation structure are significant. On the other hand, the isolating effect of seismic damaged structure will be decreased obviously. Acceleration of lower masonry may be larger than those of the other two models. The negative impact must be taken into account in the design.