桩-土动力相互作用对连续梁桥半主动控制的影响研究

STUDY ON THE INFLUENCE OF PILE-SOIL INTERACTION UPON SEMI-ACTIVE CONTROL OF CONTINUOUS BEAM BRIDGE

建立刚性地基和桩土相互作用两种模式的整体桥梁有限元模型,在桥梁支座部位设置线性粘滞阻尼器,计算桥梁在地震动作用下未施加控制和半主动控制的地震反应,探讨了桩土动力相互作用对连续梁桥地震反应半主动控制的影响以及半主动控制的减震效果。结果表明,桩土动力相互作用使连续梁桥自振周期增大,半主动控制的减震效果也相应增大,而最终的桥梁最大位移反应数值比较接近,最大内力数值更加减小,桩土动力相互作用对连续梁桥半主动控制系统减震效果的不利影响非常小,充分显示了半主动控制的优越性。

Two whole bridge finite element models, i.e., bridge of rigid foundation mode and of pile-soil interaction mode are established. The linear viscous fluid dampers are set at the locations of pedestals. The seismic responses of the bridges of no control and under semi-active control are calculated. The influence of pile-soil interaction upon semi-active control of continuous beam bridge and the vibration-reduction effect of semi-active control are investigated. The results indicate that the pile-soil interaction makes the vibration period of bridge longer, and the vibration-reduction effect of semi-active control becomes stronger correspondingly. The final maximal displacements of the two bridges are of small difference, while the internal forces in the bridge of pile-soil interaction mode turn into lesser. The disadvantageous effect of pile-soil interaction upon semi-active control of continuous beam bridge is of small extent and its merits are obvious.