小半径曲线桥振动台试验模型设计与试验研究

针对某小半径曲线桥,设计1/16的缩尺模型,开展考虑桩-土-桥梁结构动力相互作用的振动台试验研究。主要对振动台试验的模型设计和试验的实施进行阐述,通过对试验部分结果和现象进行分析,初步得出桩-土-结构体系的振动响应规律,探讨了小半径曲线桥破坏特征与破坏模式。结果表明:随着输入地震动强度的增大,结构的频率整体呈下降趋势,阻尼比整体呈增大趋势;结构的加速度反应从桩基底部向上至桥面,随着高度的增加整体呈增大趋势;桩基顶部应变和动土压力幅值最大,墩柱应变大于桩基应变;试验过程中观测到了桥体扭转反应,试验也展现了落梁、支座脱落、裂缝贯穿、局部混凝土压碎等震害现象。

Design and analysis of shaking table test of a small radius curved bridge

Focusing on a small radius curved bridge,the shaking table test of a 1/16 scaled model considering pile-soil-bridge structure dynamic interaction was accomplished.The model design and implementation of the shaking table tests were demonstrated.The vibration response of pile-soil-bridge structure was obtained preliminarily using test data and observed phenomena,and the failure features and modes of the scaled model were investigated.The results showed that the frequencies were in a downtrend but damping ratios tended to increase with the intensity of input ground motion;from the bottom of pile to the bridge deck,acceleration responses of structure tended to increase;the strain and dynamic soil pressure amplitudes of pile top were maximum,and the strain of pier column was larger than pile;torsion phenomenon was observed in the test,and a series of earthquake damage phenomena,such as girder falling,bearing failure,crack penetration and local concrete crushing,were demonstrated during the test.