Development of a Mobile Laser Measurement System for Subway Tunnel Deformation Detection

Area of Science:

• Geotechnical Engineering
• Civil Engineering
• Surveying Technology

Background:

• Mobile laser measurement systems offer enhanced efficiency and precision for metro tunnel deformation detection.
• Existing systems face challenges such as high costs, limited support, and technological barriers.

Purpose of the Study:

• To develop a novel mobile laser measurement system tailored for metro tunnel deformation detection.
• To enhance the accuracy and reliability of deformation monitoring through multi-sensor integration and advanced algorithms.

Main Methods:

• Integration of a rail inspection vehicle, 3D laser scanner, odometer, and inclinometer for synchronized data acquisition.
• Application of point cloud pre-processing algorithms including denoising, centerline calculation, and roadbed removal.
• Utilizing ellipse fitting for evaluating tunnel section convergence and inter-ring misalignment, and the ray method for detecting encroachments.

Main Results:

• Experimental validation on the Xuzhou Metro confirmed the system's reliability and stability for routine deformation detection.
• The proposed pre-processing algorithm effectively identifies and eliminates disturbed points.
• The system accurately identifies tunnel encroachments and provides essential related information.

Conclusions:

• The developed mobile laser measurement system provides an efficient and reliable solution for metro tunnel deformation detection.
• The system demonstrates significant potential for future advancements and broader applications in tunnel infrastructure monitoring.