Shaking table test research for curved rigid bridge under near-fault pulse ground motions

To study the structure response of curved bridges under the action of near-fault pulse ground motion, a test model for a curved bridge with the similar ratio of 1: 10 was designed. The shaking table tests of horizontal seismic excitation with the forward-directivity effect, the fling-step effect and the non-speed pulse records were carried out, respectively. The results show that the structural response of the curved bridge under the near-fault pulse effect ground motion is significantly higher than that with non-speed pulse ground motion. The radial displacement of the mid-span and the relative displacement of the piers under the forward-directivity effect ground motion are obvious. The tangential displacement of the mid-span, the displacement of the beam end, and the displacement of the bearings under the near-fault ground motion are related to the relative position between the curved bridge and the fault. The displacement response of the main girder has spatial characteristics, and the main girder rotates while moving horizontally. The rotation effect of the main girder is excited easily by the bidirectional excitation of the near-fault pulse ground motion. The rotation effect of the main girder makes the beam end displacement and the bearing displacement more obviously at the low pier, which can cause the girder to fall and the bearing to shed. In seismic design and analysis, the effects of the near-fault pulse ground motion and the relative position relationship between the curved bridge and the fault on the structural response should be considered. © 2019, Editorial Department of Journal of Southeast University. All right reserved.