厦漳跨海大桥北汊主桥振动台试验研究

Shaking Table Test Study of North Main Bridge of Xiazhang Sea-Crossing Bridge

为了研究阻尼器和不同地震激励方式对厦漳跨海大桥北汊主桥抗震性能的影响,以及为计算分析提供依据,设计制作了1∶50的有机玻璃全桥模型,利用地震台阵对模型桥进行了白噪声激励和模拟地震试验,分析模型的动力特性及一致激励、行波效应以及带阻尼器时的地震响应。试验结果表明:试验模型模态测试结果和计算结果吻合较好;在顺桥向地震作用下,阻尼器减震效果明显;纵向行波效应对大桥影响较大,横向行波效应对大桥影响很小;大桥桥塔各向地震响应是解耦的。因此,可以选择适宜的阻尼器,以提高大桥的抗震性能;可以采用纵向+竖向和横向+竖向2种地震输入方式进行大桥的抗震分析。

To study the influences of the dampers and different seismic excitation ways on the seismic performance of the north main bridge of the Xiazhang Sea-Crossing Bridge and to provide the basis for the calculation and analysis, an organic glass model in scale of 1 ： 50 for the whole bridge of the bridge was designed and fabricated. The seismologic array was used to carry out the white noise excitation and earthquake simulation tests for the model bridge. The dynamic characteristics of the model and the seismic responses of the model with dampers under the uniform excitation and traveling wave effect excitation were analyzed. The results of the tests and analysis show that the tests of the model modes are agreeable with the calculations. Under the action of the earthquake in the longitudinal direction of the bridge, the seismic mitigation effect of the dampers is notable. The influence of the longitudinal traveling wave effect on the bridge is great while that of the transverse traveling wave effect is quite little. The seismic responses of the pylons of the bridge in all directions are deeoupling and therefore the appropriate dampers may be chosen to improve the seismic performance of the bridge and the two ways of the longitudinal＋vertical and the transverse＋vertical seismic input can be used to carry out the seismic analysis of the bridge.