Real-time deformation monitoring of large diameter shield tunnel based on multi-sensor data fusion technique

The measurement of the shield tunnel deformation is an important tool to ensure structural integrity. The structural "deformation" of the tunnel is not merely a simple geometric deformation, which includes the elastic deformation of the segments and the rigid deformation caused by the opening and misalignment of the joints between the segments. Therefore, it is hard to monitor the deformation only relying on a single device. In this study, a data-fusion computing algorithm based on a fusion of rotation and strain measurements is proposed to improve the accuracy of tunnel deformation monitoring without the need of reference frame. SmartRock sensor was utilized to record rotation and the strain change of tunnel segments. Kalman filter was used as the fusion technique. The algorithm was successfully applied in the project of Jinan Yellow River tunnel, China. The result was compared with the result obtained by laser scanner and shows good consistency.