A prefabricated subway station (PSS) represents an efficient and environmentally friendly construction approach; however, the complexity of its assembly process can induce structural disturbance responses within the base slab structure. This study systematically investigates the mechanical behavior and disturbance characteristics of the base slab during assembly. It establishes a high-precision, large-scale strain monitoring system for PSS construction by integrating distributed fiber optic sensing (DFOS) and fiber Bragg grating (FBG) technologies. Furthermore, a structural disturbance safety classification framework is developed using Principal Component Analysis (PCA) in combination with K -means clustering to quantitively evaluate disturbance severity. The results indicate that: (a) FBG-based time-series monitoring at critical supports reveals pronounced stress imbalance during the initial one-sided assembly stage. Rapid placement of prefabricated components introduces transient impact loads, which may lead to irreversible structural damage, whereas segmented and staged placement effectively reduces impact intensity and mitigates disturbance effects. (b) DFOS-based distributed monitoring demonstrates that the base slab undergoes pronounced compression-bending interaction during top slab assembly. One-sided wall installation induces a bending moment difference of 63%–188% between the slab ends, which is decreased to 9.6% after the top slab is installed, indicating improved structural integrity. (c) PCA- K -means analysis quantifies the average disturbance degrees for monitoring stages S2, S3, and S4 as 0.21, 0.29, and 0.34, respectively. Region exceeding the defined disturbance threshold are more prone to crack formation, demonstrating that the proposed method is effective in identifying structurally vulnerable zones during assembly.
Hong et al. (Sun,) studied this question.