关键词: PBA工法, 地铁车站, 钢管混凝土柱, 拱结构, 矢跨比, 有限元分析

Abstract: To investigate the effect of top arch risespan ratio on the force safety of the concretefilled steel tubular(CFST) column and ground deformation of metro stations, a case study is conducted on the Xiangheyuan station on Beijing metro line 17. Then, the mechanical theoretical model of arch is established, and the variation rule of internal force of the arch foot is obtained through theoretical analysis. Finally, combined with numerical simulation method and field measured data analysis, the force characteristic of CFST column and the regularity of surface deformation under different top arch risespan ratios are obtained. The results reveal the following: (1) Under different top arch risespan ratios, the maximum shear force and bending moment of the CFST column appear around the middle plate. (2) As the risespan ratio increases, the maximum axial force and surface settlement tend to decrease and then increase, which is consistent with the results of theoretical analysis. (3) At the stage of the secondary lining buckle arch construction in the pilebeamarch station, the increment of axial force of the CFST column increases the most, and the axial force of the CFST column at this stage is more than 75% of the final axial force. (4) After the main structure of the station is completed, the maximum surface settlement is above the stations′ middle line, and the settlement trough curves are symmetrically distributed in the stations′ middle line, which is the same as the symmetric form of the pilot tunnel. The station with a small roof arch and span has less uneven settlement as a result of construction, which aids to control surface deformation.

Key words:  , pile-beam-arch method, metro station, concrete-filled steel tubular column, arch structure, risespan ratio, finite element analysis