行波效应对非对称多塔矮塔斜拉桥地震响应的影响

Effect of travelling wave on seismic response of asymmetry muti-pylon extradosed cable-stayed bridge

为研究行波效应对非对称多塔矮塔斜拉桥地震响应的影响,本文基于某工程实例,依据大质量法原理,采用动态时程法分析行波效应对结构关键位置内力和变形的影响,且将效应与一致激励响应进行对比。结果表明:行波激励对中墩底和近波源侧的主塔底抗弯和抗剪均不利;各塔顶顺桥向位移在行波激励下差异显著,较一致激励响应最大增加约18%;行波方向对非对称性不显著的结构影响较小。

In order to study the influence of traveling wave effect on the seismic response of asymmetric multi-pylon extradosed cable-stayed bridge, based on an engineering example, according to the principle of large mass method, the influence of traveling wave effect on the inner force and deformation of the key position of the bridge are analyzed using dynamic time history method, and the response with the uniform excitation response are compared. The results show that the traveling wave excitation is unfavorable to the bending and shear resistance of the bottom of the middle pier and the main tower near the wave source side;the displacement of the top of each tower along the bridge direction is significantly different under the traveling wave excitation, with a maximum increase of about 18% compared with the uniform excitation response;the direction of traveling wave has little effect on the structure without significant asymmetry.