采用粘滞阻尼器的高桥墩连续刚构桥减震控制研究

Seismic Control of High Pier Continuous Rigid-frame Bridges Using Viscous Dampers

为研究液体粘滞阻尼器参数对不同强度地震作用下高墩刚构桥减震控制的影响,以某墩高65 m的刚构桥为案例,采用midas Civil 2020建立有限元模型,并进行非线性时程分析。研究结果表明:梁端位移、墩底内力总体上均随着阻尼系数C增加而增大,随着阻尼指数α的增大而减小,综合考虑梁端位移、墩底内力及液体粘滞阻尼器的加工制造难度等因素,一般地震作用下,建议桥的液体粘滞阻尼器参数C取6000 kN(m/s)^(-α),α取0.4;强震时,C取7000 kN(m/s)^(-α),α取0.4。同参数阻尼器在不同强度地震作用下减震效果存在差异,强震作用下,顺桥向梁端位移、3#墩底弯矩、3#墩底剪力最大减震率为48%、23%、35%。在一般地震和强震作用下,各墩墩顶弯矩、剪力、位移的平均减震率分别为11.0%、15.9%、32.3%和46.1%、44.0%、45.1%。表明地震作用下,液体粘滞阻尼器适用于高墩刚构桥的减震设计。

To investigate the influence of liquid viscous damper parameters on the seismic control of high-pier rigid frame bridges under different intensity earthquakes, a 65 m high-pier rigid frame bridge was chosen as the engineering case study. The finite element model was established using midas Civil 2020, and nonlinear time history analysis was performed. The research findings indicate that overall, the beam-end displacement and pier base internal forces increase with an increase in the damping coefficient C, while they decrease with an increase in the damping exponent α. Considering factors such as beam-end displacement, pier base internal forces, and the manufacturing difficulty of liquid viscous dampers, it is recommended that for general seismic actions, the damping parameters of the bridge's liquid viscous damper be set at C=6000 kN(m/s)^(-α) and α=0.4. For strong earthquakes, C=7000 kN(m/s)^(-α) and α=0.4 are suggested. It is observed that the same parameter damper exhibits different seismic reduction effects under different intensity earthquakes. Under strong earthquake excitation, the maximum reduction rates for the along-bridge beam-end displacement, 3rd pier base bending moment, and 3rd pier base shear are 48%, 23% and 35% respectively. Under general and strong earthquake excitations, the average reduction rates for the bending moment, shear force, and displacement at the top of each pier are 11.0%,15.9%,32.3% and 46.1%,44.0%,45.1% respectively. Overall, these findings indicate that liquid viscous dampers are suitable for seismic design in high-pier rigid frame bridges under earthquake excitation.