Comparative Study on the Small Radius Curved Bridge and Simplified Models by Shaking Table Tests

Abstract

Three experimental structural models of a small radius curved bridge, which include a three-span small radius curved bridge model and its corresponding two different simplified models that are widely used (e.g., one mass simplified model and one single pier simplified model), will be constructed, and then three bridge structure–foundation soil system models will be designed to carry out shaking table tests. From the shaking table tests on the three models under different input motions, the dynamic soil–structure interaction effects on the dynamic characteristics, seismic response rules, and damage modes of the three models will be studied and compared. Before the test, the measured fundamental frequency of the single pier simplified model was minimum and that of the mass simplified model was maximum in the three test models. In the test, with an increase in the input motion peak ground acceleration (PGA), the soil disturbance and deformation increased gradually, and the foundation soil separated gradually from the model structures, and local damage to the structures occurred, and the fundamental frequency of the curved bridge model structure decreased most significantly in the three models. The test phenomena and measured results indicate that the single pier simplified model could be used to approximately simulate the acceleration and displacement responses of the fixed pier and corresponding pile of the curved bridge, and the single pier simplified model could be used to approximately simulate the strain response of the fixed pier and corresponding pile. The mass simplified model was not suitable to simulate the acceleration, displacement, and strain responses of the fixed pier and corresponding pile. It is not appropriate to use the mass simplified model and the single pier simplified model to simulate the pile–soil contact pressure of the fixed pier model. In addition, the single pier simplified model could not reflect the torsion characteristics of a curved bridge.