关键词: 装配式车站, 整体结构, 缩尺试验, 力学性能, 顶管法

Abstract: A case study is conducted on the Shasan station of the Shenzhen metro line 12 Phase Ⅱ project to investigate the overall mechanical performance of prefabricated rectangular metro stations with large sections constructed using the pipe-jacking method. A 1:5 scale model of the station is developed to simulate various construction and operational conditions based on the station′s design scheme and finite element analysis. Model tests are performed to analyze the structural mechanical behavior under different conditions. By incrementally increasing the applied loads, the ultimate bearing capacity of the station is assessed, and the experimental results are compared with those obtained through finite element analysis. The test results are summarized as follows: (1) Under construction and normal operating conditions, the station structure remains primarily within the elastic deformation range. The maximum crack width on the top slab is less than 0.2 mm, and the internal forces and deformations throughout the structure meet the relevant design requirements. (2) When the static load reaches 2.3 times the design load, extensive cracking appears on the top slab and at the mid-span of the top supporting beams, indicating widespread yielding, a sharp increase in deformation, and the emergence of an inflection point on the load-displacement curve. At 2.5 times the design load, diagonal cracks develope on the supports of the top slab, signifying that the structure has reached its ultimate bearing capacity. (3) The structural form adopted at the Shasan station demonstrates a high safety margin and meets all design requirements. (4) The two-dimensional finite element analysis method shows poor applicability for this structural form and should be revised or replaced with a three-dimensional analysis approach.

Key words: prefabricated station, overall structure, scale model, mechanical performance, pipe-jacking method