摘要
为探究盖挖逆作地铁车站施工阶段结构在最不利工况下的抗火性能,基于有限元分析软件Abaqus,采用相继“热-力耦合”方法建立施工阶段典型最不利工况(底板与底层侧墙未施作阶段)的有限元模型,并通过试验数据验证了模型的有效性。基于该模型,系统分析了结构温度场分布、变形特征及耐火极限等关键抗火性能指标。结果表明:施工阶段结构最不利位置集中于底层中立柱;围护桩对顶板边跨的竖向约束作用显著,但中板热膨胀变形会在中立柱产生不可忽略的附加偏心距,即便防火保护层达到设计厚度,施工阶段最不利工况结构的耐火极限仍略低于规范规定的3 h要求。本文成果可为同类盖挖逆作地铁车站施工阶段的抗火安全设计与评估提供参考。
To explore the fire resistance performance of structures in metro stations constructed by the top-down method under the most unfavorable conditions during the construction stage,based on a finite element analysis software Abaqus,the finite element model for the typical most unfavorable working condition(i.e.,the stage where the bottom slab and the lowest side walls are not yet constructed)was established using the sequential“thermal-mechanical coupling”method,and based on the test data the validity of the model is verified.Based on this model,key fire resistance performance indicators such as the temperature field distribution,deformation characteristics,and fire resistance limit of the structure are systematically analyzed.The results indicate that the most unfavorable location during the construction stage is concentrated at the middle columns of the lowest level.The enclosure piles provide significant vertical restraint to the edge spans of the top slab,while the thermal expansion deformation of the middle slab induces non-negligible additional eccentricities in the middle columns.Even when the fire protection layer meets the designed thickness,the fire resistance limit of the structure under the most unfavorable construction conditions remains slightly below the 3-hour requirement specified by the relevant codes.The findings of this study can provide references for the fire safety design and assessment of similar metro stations constructed with the top-down method during the construction stage.
作者
徐光朋
于明
吴宪财
张波
XU Guangpeng;YU Ming;WU Xiancai;ZHANG Bo(Northeast Branch,China Construction Eighth Engineering Division Co.,Ltd.,Dalian 116021,Liaoning,China;Department of Architectural Engineering,Liaoning Provincial College of Communications,Shenyang 110123,Liaoning,China)
出处
《工程建设》
2026年第1期72-79,共8页
Engineering Construction
关键词
地铁车站
盖挖逆作
施工阶段
抗火性能
有限元分析
metro station
top-down construction method
construction phase
fire resistance performance
finite element analysis
