高铁隔震桥梁模拟地震振动台试验研究

Analysis of Isolated High Speed Railway Bridge by Pseudo-earthquake Shaking Table Tests

为研究高速铁路桥梁采用摩擦摆支座后的减隔震性能,对一跨典型32.5 m高铁简支梁桥进行了试验。依据经典力学原理推导双凹面摩擦摆支座的水平力-位移滞回模型并分析其力学性能参数,设计制作了符合高铁隔震桥梁要求的隔震支座。隔震支座的低周反复加载试验显示:双折线滞回模型能有效模拟双凹面摩擦摆支座的本构关系。设计缩尺比1∶13的高铁隔震桥梁模型,并选用2条地震动记录进行模拟地震振动台试验。试验中测量了不同抗震设防烈度地震作用下模型结构振动台试验的响应,包括主梁和墩顶的加速度、位移,摩擦摆支座的剪切变形,墩底钢筋和混凝土的应变。试验结果表明:双凹面摩擦摆支座能够有效消耗地震能量,减小桥梁的动力响应,且地震强度越大隔震桥梁模型的减震效果越好。

In order to study the seismic isolation performance of the high speed railway bridge by using the friction pendulum bearing,a standard 32.5 m high speed railway simply supported girder bridge was tested.Based on the principle of classical mechanics,the horizontal force-displacement hysteretic model of the double concave friction pendulum bearing was derived and its mechanical properties were analyzed.An isolation bearing was designed to meet the requirements of the isolated high speed railway bridge.The low cycle repeated loading test of isolation bearing shows that the constitutive relation of the double concave friction pendulum bearing can be simulated by the bilinear elastic-plastic hysteretic model.The isolated bridge model of 1∶13 scale was designed.Two typical earthquake records were selected to carry out the pseudo-earthquake shaking table test.The responses of the shaking table test of model under the earthquake actions of different seismic fortif ication intensities were measured in the test,including accelerations and displacements of the main girder and pier top,shear deformation of the friction pendulum bearing,the strain of rebar and concrete at the bottom of the pier.The experimental results show that the double concave friction pendulum bearing can effectively dissipate the earthquake energy and reduce the dynamic response of bridge.The greater the earthquake intensity,the better the seismic isolation effect of the isolated bridge model.