CAJ | 학술논문

大跨度公铁两用钢桁梁斜拉桥是一种技术复杂的特殊桥梁，为系统地把握该类型桥梁结构在地震作用下的动力响应规律，总结该类桥梁的总体结构特征，统计分析5座公铁两用大桥的结构动力特性值，利用有限元数值仿真方法分析不同结构抗震约束体系的地震响应特点，统计粘滞阻尼器的减震效果并解释效果差异的原因。研究表明：大跨度公铁两用斜拉桥的竖向刚度与公路斜拉桥相比有明显差异，前者的竖弯基频比后者平均高20％左右；在多种结构抗震约束体系中，具有耗能显著特点的液体粘滞阻尼器体系是一种较为理想的结构抗震支承体系；采用粘滞阻尼器后，6座大桥桥塔的弯矩减震率呈现20％左右与60％以上两种不同表现结果，该现象主要与地震动输入的长周期成分取值有关；由于剪力比弯矩的阶次低，导致桥塔剪力比弯矩的减震效果低；粘滞阻尼器对梁端位移的减震效果显著，可达到60％～80％。
대과도공철량용강항량사랍교시일충기술복잡적특수교량，위계통지파악해류형교량결구재지진작용하적동력향응규률，총결해류교량적총체결구특정，통계분석5좌공철량용대교적결구동력특성치，이용유한원수치방진방법분석불동결구항진약속체계적지진향응특점，통계점체조니기적감진효과병해석효과차이적원인。연구표명：대과도공철량용사랍교적수향강도여공로사랍교상비유명현차이，전자적수만기빈비후자평균고20％좌우；재다충결구항진약속체계중，구유모능현저특점적액체점체조니기체계시일충교위이상적결구항진지승체계；채용점체조니기후，6좌대교교탑적만구감진솔정현20％좌우여60％이상량충불동표현결과，해현상주요여지진동수입적장주기성분취치유관；유우전력비만구적계차저，도치교탑전력비만구적감진효과저；점체조니기대량단위이적감진효과현저，가체도60％～80％。
T he long span rail‐cum‐road steel truss girder cable‐stayed bridge is a type of the special bridge of technical complexity . To systematically understand the structural dynamic re‐sponse law s of such type of the bridges under the action of earthquake ,the general structural char‐acteristics of the bridges were summed up and the structural dynamic characteristic values of 5 long span rail‐cum‐road steel truss girder cable‐stayed bridges were statistically analyzed .The seismic response characteristics of the different structural seismic restraint systems were analyzed ,using the finite element numerical simulation ,the damping effect of the fluid viscous dampers was statis‐tically collected and the differences of the damping effect were illustrated .The results of the analy‐sis demonstrate that the vertical stiffness of a long span rail‐cum‐road steel truss girder cable‐stayed bridge is significantly different from that of a long span highway steel truss girder cable‐stayed bridge and the vertical bending base frequency of the former is averagely 20% higher than that of the latter .Among the varied structural seismic restraint systems ,the fluid viscous damper system characterized by the significant energy dissipation is an ideal structural seismic resistance support system .After the fluid viscous dampes are used ,the moment damping rates of the pylons of the 6 cable‐stayed bridges exhibit two kinds of the results of about 20% and above 60% .This phenomenon is mainly related to the values of long period components of the ground motion in‐put .Because the orders of the shear are lower than those of the moment ,the damping effect of the shear of the pylons is low er than that of the moment . T he damping effect of the viscous dampers on the girder end displacement is significant and the effect can reach 60% ~80% .