Bidirectional shaking table tests of a low-cost friction sliding system with flat-inclined surfaces |
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| Authors: | Miguel B Brito Mitsuyoshi Akiyama Yoshitaka Ichikawa Hiroki Yamaguchi Riki Honda Naomitsu Ishigaki |
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| Institution: | 1. Department of Civil and Environmental Engineering, Waseda University, Tokyo, Japan;2. Department of International Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan;3. Transportation & Urban Development Division, Nippon Koei., Ltd., Tokyo, Japan |
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| Abstract: | A novel low-cost friction sliding system for bidirectional excitation is developed to improve the seismic performance of reinforced concrete (RC) bridge piers. The sliding system is a spherical prototype developed by combining a central flat surface with an inclined spherical segment, characterized by stable oscillation and a large reduction in response accelerations on the flat surface. The inclined part provides a restoring force that limits the residual displacements of the system. Conventional steel and concrete are employed to construct a flat-inclined spherical surface atop an RC pier. The seismic forces are dissipated through the frictions generated during the sliding movements; hence, the seismic resilience of bridges can be ensured with a low-cost design solution. The proposed system is fabricated utilizing a mold created by a three-dimensional printer, which facilitates the use of conventional concrete to construct spherical shapes. The concrete surface is lubricated with a resin material to prevent abrasion from multiple input ground motions. To demonstrate the effectiveness of the system, bidirectional shaking table tests are conducted in the longitudinal and transverse directions of a scaled bridge model. The effect of the inclination angle and the flat surface size is investigated. The results demonstrate a large decrease in response acceleration when the system exhibits circular sliding displacement. Furthermore, the inclination angle that generates the smallest residual displacement is identified experimentally. |
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| Keywords: | 3D printer bidirectional motion friction sliding system RC bridge pier seismic resilience |
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