斜拉桥横向减震振动台试验

Shaking table tests for transverse aseismic control of cable-stayed bridges

为了研究弹塑性阻尼器对斜拉桥横向地震反应的减震效果,以一座独塔斜拉桥为研究对象,设计了1∶20大比例缩尺的全桥振动台模型,采用一条远场波和一条近场波作为地震输入,对该模型进行了全桥横向振动台试验。试验结果表明,与塔梁、墩梁横向固定连接相比,塔梁、墩梁横向采用弹塑性阻尼器连接能有效减小桥塔横向地震响应,如在远场和近场地震输入下,塔底截面钢筋应变分别最大减小了40%和10%;但在近场地震输入下,弹塑性阻尼器变形约为远场地震输入时的3.6~4.6倍,加载完成后产生明显的残余变形。通过对比数值和试验结果可知,数值结果与试验结果较接近、吻合较好。

Based on a single-tower cable-stayed bridge,a 1∶20 large scale full bridge model for shaking table tests was designed to study the effectiveness of elastic-plastic damper to reduce transverse seismic responses of the cable-stayed bridge. Both a far-field ground motion wave and a near-field one were taken as seismic inputs for the bridge model 's shaking table tests. Test results showed that comparing to a rigid connection of tower-deck and pier-deck,tower-deck connected to pier-deck with elastic-plastic dampers effectively reduces transverse seismic responses of the tower; under the action of a far-field ground motion wave and a near field one,the reinforcing bar strain of the tower bottom section can be reduced by 40% and 10%,respectively; however,under the action of a near-field ground motion wave,the elastic-plastic damper's deformation is 3. 6 ~ 4. 6 times of that under the action of a far-field one,it produces obvious residual deformation after loading is completed. Comparing the test results with those of numerical analysis,both of them agreed well.