基于Opensees的铁路空心高墩地震反应研究

研究高墩在强震作用下的地震反应。以铁路连续梁桥为例,基于抗震模拟软件Opensees,建立一个90 m的空心高墩,考虑高阶振型,进行非线性动力时程分析,求出加速度从0.1g至0.6g时墩顶位移、墩底弯矩的变化规律及塑性铰的形成和扩展情况。结果表明,加速度从0.1g调整为0.2g,0.4g,0.6g时,墩顶位移分别增加1.35,2.79,4.6倍,墩底弯矩分别增加1.49,2.54,3.38倍。墩底首先进入塑性区,墩中部后进入塑性区,塑性区的长度分别向墩底和墩顶扩展,向墩底比向墩顶扩展的更快更广泛。因此,高墩设计中不仅在墩底部位,也要在墩身中部布置足够的箍筋。

Research on Seismic Response of High Hollow Pier of Railway Bridge Based on Opensees

The purpose of this paper was to ascertain the seismic response of high piers under the action of strong earthquake. Taking continuous girder bridge on railway as examples, based on seismic simulation software Opensees,considering higher-order vibration mode,this paper established a model of a high hollow pier of 90m in height and carried out nonlinear dynamic time-history analysis. Therefore, as the accelerated speed was adjusted from 0. 1g to 0. 6g,the change patterns of the pier top's displacement and pier bottom's bending moment were obtained,and the situation of formation and development of the plastic hinge was also obtained. The results show that:( a) As the accelerated speed is adjusted from 0. 1g to 0. 2g,0. 4g,0. 6g respectively,the pier top's displacement will increase by 1. 35,2. 79,4. 6 times respectively,while the pier bottom's bending moment will increase by 1. 49, 2. 54,3. 38 times respectively.( b) The pier bottom first gets into the plastic zone,followed by the middle part of the pier; then the length of the plastic zone spreads respectively towards the bottom and the top of the pier,while the spreading towards the top is faster and wider than towards the bottom. Therefore,the paper suggests that in the design of high pier,it is necessary to arrange sufficient stirrups not only at the bottom of a pier but at the middle part of the pier as well.