Measures to Improve Seismic Resistance by Fuse Mechanism in Pier Structures

In Japan, temporary pier structures are designed to withstand earthquakes in consideration of their short service life, and seismic inputs exceeding the design are also expected. In order to confirm the deformation behavior of the fuse mechanism in this temporary pier structure, a fundamental study was conducted using a model specimen. The strength test results showed that the fuse mechanism behaved similar to a rigid body, and then the mortar fuse failed. After the failure of the mortar fuse, the reaction force was generated by the addition of the residual bearing capacity of the mortar fuse and the reaction force of the coil spring. The dynamic loading test results showed that the CFT columns contacted the remaining portion of the fuse after the mortar fuse ruptured, temporarily increasing the maximum response acceleration to 35 m/s2, but the response period became longer, indicating the deformation behavior of the fuse mechanism. In addition, the maximum load of the mortar fuse mechanism and the natural period after the mortar fuse rupture were calculated from the design values of the mortar fuse strength and the spring constant of the coil spring.