基于pushover法的地铁车站柱墙剪力比研究

层间位移角作为一项重要的抗震性能指标，往往用于评估地上或地下结构在正常使用条件下的水平位移，从而确保结构应具备的刚度。然而，由于地下地铁车站结构埋置于土体之中，受到周围土层的约束，其在地震作用下的层间位移角量值小、不易控制与监测。鉴于此，文章以典型两层三跨地铁车站为研究对象，基于大型有限元程序ABAQUS建立了土 车站结构非线性相互作用分析模型，开展了pushover弹塑性推覆分析，得到了车站结构各构件的剪力—层间位移角全过程曲线，并在此基础上确定了构件的关键性能点及其阈值，研究了地铁车站结构不同性能状态下中柱和侧墙剪力分配规律。分析结果表明，地铁车站下层中柱首先进入破坏状态；下层中柱剪力先增加后减小，但相较于车站侧墙，中柱分配到的剪力比例一直下降。在此基础上，进一步提出了归一化的柱墙剪力比作为评价地铁车站抗震性能的力学指标，可有效弥补单一位移指标的不足。

Column-wall shear ratio of subway station based on pushover method

As an important seismic performance index, the inter-story drift radio is often used to evaluate the horizontal displacement of the above ground or underground structure to ensure the stiffness in serviceability states. However, because the underground subway station structure is buried in soil and constrained by the surrounding soil, the inter-story drift radio during earthquake is small and difficult to control and monitor. In view of this, based on the finite element program ABAQUS, the nonlinear soil-structure-interaction model is established in this paper, and the elastoplastic pushover analysis is carried out. The whole process curve of shear force-story drift of each structural component is obtained, and the key performance points and their thresholds are further determined. The shear distribution between column and sidewall in different performance states of station structure is also studied. Results show that the column in lower story first enters the failure state; the shear force of column in lower story increases first and then decreases, but compared with the side wall of the station, the proportion of story shear force allocated to the column has been decreasing. On this basis, the normalized shear ratio of column to sidewall is proposed as a mechanical index to evaluate the seismic performance of subway stations, which can effectively make up for the deficiency of single displacement index.