Research on Parameter Inversion and Settlement Prediction for Metro Shield Tunneling beneath Existing Building Clusters

Objective To address the challenge of determining key stratum parameters during shield tunneling beneath existing building clusters, a Beluga Whale Optimization-FLAC3D (BWO-FLAC3D) method is proposed,which utilizes settlement monitoring data to enable the non-destructive inversion of stratum parameters.

Method The theoretical framework of the BWO-FLAC3D method is introduced. This method treats the error between simulated ground settlements and measured settlements as the objective function, with stratum parameters serving as optimization variables, and employs the unique Beluga Whale Optimization algorithm to search for the global minimum of the objective function, thereby deriving the corresponding stratum parameters. The applicability of the method is validated through a case project study from Guangzhou Metro Line 12.

Result & Conclusion  The proposed method can accurately invert the relevant stratum parameters and significantly reduce the processing time. Furthermore, updating the inverted parameters according to actual construction conditions enables the prediction of ground settlement behind the excavation face during shield tunneling advancement. The predicted results show relatively small errors compared to the measured results.