托换对津滨轻轨桥梁抗震性能的影响分析

Effect on Seismic Performance of Bridge for Jin-bin Mass Transit by Pier-underpinning

以津滨轻轨桥墩托换工程为研究对象,考虑桩-土共同作用,运用ANSYS分析托换前与托换后结构的自振特性,并采用反应谱法和时程分析法计算托换前及托换后桥梁结构的地震反应。结果表明,托换后的桥梁结构基本周期比托换前减小了,地震荷载作用下,桥梁墩底特别是托换桥墩底部的最大剪力值和弯矩值较托换前大幅增加,而墩顶位移最大值则大幅减小,说明托换使得桥梁结构的整体刚度增加了,托换后的桥梁结构体系具有较好的抗震性能。

The pier-underpinning of Jin-bin mass transit is taken as the research object, and ANSYS sott- ware is used in the vibration characteristics and dynamic responses analysis and pile-soil common function is con- sidered in the numerical simulation. The response Spectrum method and time history method are used to calculate the dynamic responses of the bridge structure before and after the pier-underpinning. The results show that the basic cycle of the bridge structure becomes smaller, and the maximum shear values and the maximum bending moment values of the piers bottom increase, but the maximum deflection values of the piers top decrease after the pier-underpinning. Thus the pier-underpinning improves the stiffness and seismic performance of the bridge structure system.