地铁车站自复位中柱性能及参数变化研究

Study on Performance and Parameter Variations of Self‑centering Middle Columns in Metro Stations

摘要:

基于可恢复性抗震理念，提出一种新型中柱体系，旨在为地铁地下结构提供优异的抗震性能及自复位功能。 通过 ABAQUS 软件，模拟分析了新型柱的自复位性能、水平变形能力及抗剪承载能力等基本性能，并探讨了初始预应力值、预应力筋数量和柱头尺寸三种参数变化对新型柱性能的影响情况。结果表明：相比传统固接柱，新型柱不仅表现出良好的自复位能力，还具备明显的水平变形和损伤特征优势。适当减小初始预应力值有利于改善新型柱的自复位性能；减少预应力筋数量、增大柱头，都有利于提升小轴压比下新型柱的自复位性能，反之增加筋数、减小柱头，则有利于提升大轴压比下新型柱的自复位性能。参数变化对水平变形能力的影响仅当轴压比小于 0.7 时表现明显，该轴压比条件下，初始预应力值越小、预应力筋数量越多，新型柱变形能力越强；柱头的设置有利于新型柱变形能力的提升，但其尺寸影响并不显著；初始预应力值取 500 MPa、预应力筋设置一排、柱头半径 0.2 m 为最佳组合。参数变化对新型柱抗剪承载力影响并不明显。研究成果可为地铁地下结构可恢复性抗震体系的深入研究与设计提供参考价值。

Abstract:

Based on the concept of seismic resilience, this study proposes a new middle column system, aiming to provide excellent seismic performance and self-centering capability for metro underground structures. Using ABAQUS software, the basic performance of the new columns, including their self-centering capability, horizontal deformation capacity, and shear bearing capacity, was simulated and analyzed. The effects of three parameter variations—initial prestress value, number of prestressing tendons, and column head size—on the performance of the new columns were further investigated. The results showed that compared to traditional consolidated columns, the new columns not only demonstrated good self-centering capability but also had significant advantages in horizontal deformation and damage characteristics. Appropriately reducing the initial prestress value was beneficial for improving the self-centering capability of the new columns. Decreasing the number of prestressing tendons and increasing the column head size both enhanced the self-centering capability under low axial compression ratios, while increasing the tendon quantity and reducing the column head size were favorable for improving the self-centering capability under high axial compression ratios. The effect of parameter variation on the horizontal deformation capacity was evident only when the axial compression ratio was less than 0.7. Under the condition of this axial compression ratio, smaller initial prestress values and a greater number of prestressing tendons resulted in enhanced deformation capacity of the new columns. The incorporation of a column head was beneficial for enhancing the deformation capacity of the new columns, but its size had no significant effect. The optimal combination was an initial prestress value of 500 MPa, a single row of prestressing tendons, and a column head radius of 0.2 m. Parameter variations had little effect on the shear bearing capacity of the new columns. The research findings can provide valuable references for the further research and design of resilient seismic systems for metro underground structures.