Experimental Study on Elastic Sliding Bearings with Rotational Deformation Capacity

The pile-top seismic isolation method simplifies the foundation structure under the seismic isolation layer by installing the isolators directly on the top of the piles and contributes to cost reduction. However, the rotation deformation constraint effect of the pile-top method is smaller than that of the conventional seismically isolation applications with a relatively stiff foundation layer. As a result, the seismic isolation devices also rotate and deform as the pile-top rotates. In this study, cyclic bi-axial loading tests on special elastic sliding bearings with rotational deformation capacity were carried out, which can be implemented in the pile-top seismic isolation method. The tests were carried out to confirm the basic performance and dependence on the rotational deformation angle of the devices. According to the tests, it was shown that the friction coefficient was not affected up to the rotational deformation angle of 1/100 radians of the elastic sliding bearings. In addition, during long-period and long-duration ground motions, the response deformation may become excessive due to the change in the performance of the elastic sliding bearing. In order to confirm the performance of this elastic sliding bearing under long-period and long-duration ground motions, additional cyclic bi-axial loading tests and thermal-mechanical coupled analysis were conducted. It was observed that the friction coefficient decreases with the rising temperature of the sliding plate, and the performance of the device under long-period and long-duration ground motion was confirmed.