【摘要】 为探讨列车高速通过桥梁时传递到桥墩的振动受弹性支座的影响,建立了12个自由度的弹簧-阻尼单元模拟支座,嵌入到车-线-桥耦合振动分析模型中。以高速铁路上典型的32 m混凝土双线简支梁桥为研究对象,采用包含支座单元的车-线-桥耦合振动分析程序进行仿真计算。结果表明:车辆的轮重减载率和竖向振动加速度受支座竖向刚度的影响很小;支座竖向刚度降低,桥梁响应中的静力成分逐渐增大,动力成分则先逐渐减小,再逐渐增大;采用弹性支座,墩顶全频域内的减振效果主要取决于优势频段20Hz~80Hz频率范围的振动衰减量;弹性支座隔振系统的自振频率为10Hz~20Hz,能够吸收中高频振动,放大自身频率范围振动,反映出弹性支座在中、高频段具有很好的隔振性能。更多还原

【Abstract】 To explore the effect of elastic bearings on vibration of the pier induced by a train running through at high speeds, spring-damper elements with 12 degrees of freedom were established to simulate bearings, which were then added to a train-track-bridge coupled vibration model. A typical simply-supported box-girder bridge with a span of 32 m was studied. Based on the train-track-bridge-bearing coupled vibration model with bearing elements, numerical simulation was carried out. The results show that the wheel unloading rate and the vertical acceleration of the vehicle are only marginally influenced by the stiffness of bearings. With the stiffness of bearings decreasing, the static component of the response of the bridge increases gradually, while the dynamic component decreases initially and then increases. For elastic bearings, the vibration attenuation in the whole frequency range is mainly determined by the vibration absorption effects in the dominant frequency band at 20Hz~80Hz. Because the natural frequency of the elastic bearings system is within the frequency band at 10Hz~20Hz, vibration in the intermediate and high frequency bands can be absorbed, while the vibration of its natural frequency band can be amplified. Therefore the elastic bearings can have prominent vibration isolation performance in the middle and high frequency bands.更多还原