基于黏滞阻尼器的连续梁桥减震控制振动台试验研究

Shaking table tests for a continuous girder bridge's aseismic control with viscous dampers

目前国内外高烈度设防区域的很多桥梁均安装了黏滞阻尼器用于减震控制,其设计与布置均依据动力弹塑性理论分析和数值模拟,不仅缺乏振动台试验的验证,同时减隔震桥梁经历地震考验的相关工程实例也很少。设计并制作了孔隙式黏滞阻尼器,通过循环往复加载试验获得了其滞回曲线,进而将其安装在一座连续梁桥缩尺模型上进行了振动台试验,通过试验验证了其减震控制效果。试验结果表明:黏滞阻尼器的阻尼力随着频率的增大而增大,实测滞回曲线接近于椭圆;黏滞阻尼器对连续梁桥固定墩墩底应变和墩顶位移及活动支座的纵向位移响应均有良好的减震控制效果,不同地震波输入下的减震率有所不同,最大减震率达到50%以上。

Viscous dampers are installed on a lot of bridges located in high-intensity earthquake fortification zones for aseismic control.Their design and arrangement are always performed according to dynamic elastoplastic theoretical analysis and numerical simulation but they are lack of verification with shaking table tests,and practical engineering examples of bridges experiencing the test of earthquake are less.Here,porous type viscous dampers were designed and manufactured,and their hysteretic curves were measured through cyclic loading tests.Then these dampers were installed on a continuous girder bridge scale model to conduct shaking table tests to verify the bridge aseismic control effect.Test results showed that damping forces of viscous dampers increase with increase in loading frequency,and their measured hysteretic curves are close to an ellipse;viscous dampers have good aseismic control effects on the bridge’s fixed pier bottom strain,pier top displacement and longitudinal displacement of movable supports;there are different bridge aseismic rates under input of different earthquake waves,the maximum bridge aseismic rate can reach more than50%.