不同地震烈度下隔震连续梁桥模型振动台试验

为了研究在不同地震烈度下不同类型场地的隔震连续梁桥结构的振动特性和隔震效果,根据一座在建的两跨隔震梁桥,按1/10的比例设计了一座两跨隔震梁桥模型及试验用方形铅芯橡胶支座,并对其力学性能进行试验;在此基础上对梁桥结构模型进行了地震模拟振动台试验。结果表明:地震动的幅度和频谱成分、场地类别、地震烈度、断层等因素对隔震桥梁体系的隔震效果有很大影响;输入不同地震波和不同加速度峰值,小震时铅芯橡胶支座水平刚度较大,结构较稳定,大震时铅芯橡胶支座水平刚度较小,支座恢复力-位移滞回曲线面积较大,可以较多地耗散地震输入能量,减小能量向桥梁上部结构的传递。

Shaking Table Test of Isolated Continuous Girder Bridge Model Under Different Earthquake Intensity Excitations

In order to investigate different types of fields of the vibration properties and isolated effect of isolated continuous girder bridges under different earthquake intensity excitations,a 1/10 isolated bridge model consisting of two-span continuous deck and square lead rubber bearing(LRB) using in test were designed and mechanical characteristics of LRB were tested.Based on it,simulated shaking table test was carried out.Results show that the amplitude and ingredient of frequency spectra,site sort,earthquake intensity and fault layer have important influence on isolated effect of isolated bridges.Under different peak seismic waves and peak accelerations,the isolated bridge structure is stable because horizontal stiffness of LRB is great under minor earthquake input.Much earthquake energy is dissipated and energy transmitted to the upper part of bridge can be reduced due to areas of displacement hysteretic curves of bearing restoring force is big and horizontal stiffness of LRB is small under large earthquake input.