双幅联塔斜拉桥阻尼器布置方案和参数分析

Analysis on Arrangement Schemes and Parameters of Dampers with Coalescent Cable-Stayed Bridge

为研究黏滞阻尼器布置方案和阻尼参数变化对斜拉桥的减震效果,以某主跨为300m的双幅联体塔斜拉桥为背景进行研究。采用桥梁商用软件建立桥梁空间有限元模型,应用线性时程法对比分析了3种阻尼器布置方案(集中布置主塔处、分散布置塔墩处采用相同阻尼系数、分散布置塔墩处采用不同阻尼系数)对阻尼器参数变化的减震效果。结果表明,采用黏滞阻尼器能显著降低主梁、主塔的内力和变形;与阻尼器分散布置在塔梁处相比,阻尼器集中布置在主塔处对桥墩受力更有利,但是塔底弯矩和剪力较大;降低桥墩处阻尼器的阻尼系数对主塔受力影响很小,但会明显降低墩底弯矩和剪力,对桥墩受力有利。

To study the effect of seismic mitigation of different arrangement schemes and parameters of dampers for the coalescent cable-stayed bridge,a semi-floating system double-pylon cable-stayed bridge with twin decks and main span length of 300mis taken as background.The commercial software of bridge engineer is used to build up the spatial finite element model for the bridge and the effect of seismic mitigation of 3different arrangement schemes of dampers(the dampers are placed in three arrangement schemes:pylons with all dampers,pylons and piers with uniform damper coefficients,pylons and piers with different damper coefficients)is analyzed by the linear dynamic time-history method.The results of the analysis indicate that the bending moment and deformation of main girder and pylon can mitigate effectively with centralized arrangements of dampers in pylons,but it is adverse for the bending moment and the shear forces of pylons compared with decentralized arrangement.It has less influence on the internal forces of pylon by reducing damper coefficient,but makes an evident effect on the bending moments and the shear forces of the piers,which is favorable for the piers.