Shaking Table Test of High Pier and Small Radius Curved Bridge under Multi-point Excitation

The non-uniform stratum and uneven surface have the complicated seismic spatial variability. The seismic response of high pier and small radius curved bridge caused by the seismic specificity of this kind of terrain has not been systematically studied. According to the multi-point excitation theory of long-span structures and the similar theory of shaking table test in model structures, a high pier with small radius curved girder bridge was used as the research object. The shaking table test of real bridge model was carried out to study the seismic response laws of this kind of bridge under multi-point excitation. The results show that the designed seismic wave expansion device can meet the test requirements. The frequency of the model structure decreases rapidly and the damping ratio increases during the whole test process. The local terrain effect amplifies the seismic response of high pier and small radius curved bridge. The seismic response of high pier and small radius curved bridge is affected by different frequency spectrum seismic waves, and there is a big difference. Based on the above results, the impact of multi-point excitation should be considered in seismic design of high pier with small radius curved bridge.

Response analysis of long-period seismic action in far field to long-span continuous beam bridge with isolated high piers

In order to study the influence of far-field long-period seismic waves on high-pier and long-span continuous beam bridge, taking a high-pier and long-span continuous beam bridge with span arrangement of (95+170+95) m as an example, a numerical analysis model is established based on finite element software. According to the established wave selection criterion, 10 far-field long-period seismic records and 10 ordinary seismic records are selected from the strong earthquake record database. Using nonlinear time history analysis method, the difference of seismic response of long-span continuous beam bridge with isolated high piers under the action of ordinary ground motion and far-field long-period ground motion is studied. The results show that compared with the ordinary ground motion, the seismic response of long-span continuous beam bridge with isolated high piers is obviously increased under the action of long-period ground motion in the far field. When building isolated long-span bridges in areas with great influence of long-period ground motion in the far field, attention should be paid to the adverse effects caused by the frequency spectrum characteristics of ground motion.