【摘要】 以一座典型山区非规则梁桥为研究对象,建立了该桥梁多维多点激励下的多自由度动力计算模型,研究了该桥梁在多维多点激励下考虑支座摩擦滑移及结构碰撞等非线性因素时的抗震性能。研究结果表明:相比一维地震输入,多维地震可使结构的动力响应增加,桥墩底部弯矩需求增大;相比一致激励,多点激励可使得支座的位移需求增大,且地震波最后到达的桥墩上方支座位移最大;同时考虑多点激励和碰撞效应可使桥墩的弯矩需求增加;水平地震作用下,矮墩上部的支座容易滑动,且双向地震较单向地震更明显,三向地震输入较双向有所增强。因此,对山区非规则梁桥进行抗震设计时应有针对性地进行多维多点地震输入计算,找出结构的最大地震需求,以期指导设计。更多还原

【Abstract】 The seismic performance of a typical irregular beam bridge in mountainous areas was studied in this paper. the multiple degree of freedom dynamic calculation model of the bridge under multi-dimensional and multipoint excitation was established,and the seismic performance of the bridge under multi-dimensional and multi-point excitation considering the non-linear factors such as bearing friction,slip and structural collision was studied. The results show that when compares with the one-dimensional seismic excitation,the multi-dimensional seismic excitation can increase the dynamic response of structures and increase the demand for bending moment at the bottom of piers. Compared with the uniform excitation,the time-delay effect of seismic wave can increase the displacement demand of the rubber bearings,and the displacement of the rubber bearings above the pier where the seismic wave finally arrives is the largest. Considering the time-delay effect of seismic wave and the pounding effect,the demand for bending moment of pier increases. The bearing on the short pier is easy to slip under the excitation of one-directional horizontal earthquake input,the two-directional horizontal earthquake input is more obvious than that of the one-directional earthquake,and the three-directional earthquake input is stronger than that of the two-directional earthquake. Therefore,the seismic design of irregular beam bridges in mountainous areas should be carried out with multi-dimensional and multi-point seismic input in order to find out the maximum seismic demand of the structure for rational design.更多还原