Experimental Research On Seimic Performance Of Friction Pendulum Isolated High-rise Frame-shear Wall Structures

As one of the novel isolation devices in building engineering,the friction pendulumn system(FPS)is featured with larger vertical bearing capacity,larger horizontal displacement,and uncoupled mechanical propertries in varies directions,compared with traditional laminated rubber bearing.However,the components of an FPS are contacted by vertical compression and cannot resist any tension in the vergical direction.The applications in high-rise buildings,particularly those with large height-to-width ratios,are seriously blocked,because they are suffered from the uplifting caused by the large overturning moment.This uplifting and its influence on the super-structure shall be studied carefully.As the preliminary study,this study focuse on the reproduction of the uplifting of FPS in the high-rise building by shaking table test.This study first proposed a design method of FPS-isolated buildings,which is well adapted to the currently available seismic design code and procedure.A 12-story RC frame-shear wall was designed and further isolated by FPS.When designing the scaled model for shaking table test,a design procedure was developed to consider the similitudes of the overturning moment and the shear behavior,so that the uplifting can be well reproduced.Under the rarely-occurred earthquake,the uplifting occurred on all FPS bearings among which the largest uplifting was observed on the FPSs located under the shear walls.Under the earthquake with the PGA of 0.62 g,the maximum uplifting was 21 mm for the prototype.Although the uplifiting became more serious with the increase of input seismic intensity,the influence on the overall horizontal isolation was found very limited.All FPSs were inspected after the tests,there's no damage in the components and friction materials caused by the uplifting,implying a conservative design in the vertical bearing capacity.From the numerical analysis and the experimental results,FPS did not work under the frequently occurred earthquake.It began to slide when sustaining moderate earthquakes,and the effect of isolation was pronounced.The RC frame-shear wall structure with the designed PGA of 0.2g performed well under the ground motion with PGA of 0.8g without serious damages.The isolation still worked even with extensive uplifting occurred in most FPSs.