大跨度铁路斜拉桥地震反应影响分析

Analysis of Seismic Response Effect on Long- span Cable- stayed Railway Bridge

针对大跨度铁路斜拉桥特点,结合桥梁结构体系及抗震措施,进行了行波效应、几何非线性、弹性连接刚度及阻尼器减震措施对结构的地震反应影响分析。分析表明:行波效应使主塔控制截面的内力约增大20%;考虑结构的初始内力引起的几何非线性影响后,结构的自振周期约增大3%,对主塔的地震反应影响较小,在设计中可以忽略其影响;塔、梁间的弹性约束刚度大小对结构的地震反应影响较大,其刚度取值为1.0×105k N/m左右时,结构的抗震性能较好;粘滞阻尼器对主塔控制截面的内力及塔顶位移具有显著的减震效果。

Based on the characteristics of the long-span railway cable-stayed bridge and combined with bridge structure and seismic measures, this paper analyzes the seismic response of the structure from the aspects of traveling wave effect, geometric nonlinearity, elastic connection stiffness and damper damping. The analysis result indicates that the internal force of control section at the main tower increases about 20% at the most under traveling wave effect; considering the geometric nonlinearity effects caused by the structural initial force, the natural period of structure increases about 3%, which has little influence on seismic response of main tower, so it can be ignored in design. The elastic constraint stiff-ness between tower and girder has a significant influence on the seismic response of the structure, the seismic perform-ance of the structure is good when the stiffness value is about 1. 0 ＆#215; 105 kN/m; the viscous damper has a significant damping effect on internal force of control section at the main tower and top displacement.