地震作用下高墩大跨连续刚构桥的非线性动力稳定性能研究

Study on nonlinear dynamic stability of continuous rigid frame bridge with high piers under seismic action

地震作用下高墩大跨连续刚构桥的动力稳定性能已成控制结构安全的重要因素.本文基于ANSYS的动力稳定性分析方法—改进的动态特征值法,对某一刚构桥在考虑双重非线性下的动力稳定性进行了分析;探讨地震波特性、阻尼比、结构特性等对其动态特征值的影响.结果表明随着地震波周期、地震波幅值、结构跨度、桥墩高度中任意一个的增大或梁端约束的减弱,结构的动态特征值均呈现最小值减少、最大值增大的趋势;阻尼比越大,结构动态特征值曲线波动幅度越小.

The dynamic stability of long-span continuous rigid frame bridge with high piers under seismic action has become an important factor for the safety of the structure.In this paper,based on the dynamic stability analysis method of ANSYS-the improved dynamic eigenvalue method,the dynamic stability of a rigid frame bridge under the consideration of the double nonlinearity is analysed.The influence of seismic wave characteristics,damping ratio and structural characteristics on its dynamic eigenvalue is discussed.The result shows that with the increase of any one of seismic wave cycles,seismic wave amplitudes,structure span,height of pier or the attenuation of the beam end constraint,the minimum dynamic eigenvalue of the structure is reduced while the maximum value increased.A greater damping ratio corresponds to a smaller curve fluctuation of structure′s dynamic eigenvalue.