Tunnel inspection is an indispensable crucial component. Through the inspection process, shortcomings in tunnel construction can be identified and improved, playing an indispensable role in enhancing the quality of the project.

Purpose of Tunnel Inspection:

1. Through descriptions of the surrounding rock geological conditions and support status, rationally classify the surrounding rock and evaluate its stability.

2. Monitor the surrounding convergence displacement of tunnel arch subsidence, confirm the stability of the surrounding rock based on measurement data, assess the support effect, guide construction procedures to prevent collapse, and ensure construction safety.

3. Monitor the surrounding convergence displacements, judge the stability of the surrounding rock based on the rate and magnitude of deformation, select the appropriate timing for secondary lining support, and guide on-site construction.

4. Surface subsidence monitoring. Monitor surface settlement for shallow-tunnel sections to assess the impact of tunnel excavation on the ground surface, cross-verify with data of arch settlement.

5. Measure anchor rod length and grouting fullness to inspect anchor rod length and grouting effectiveness.

6. Selective Measurement Combinations. Monitor and assess the stability of the surrounding rock and the effectiveness of support by measuring selected items such as rock pressure, steel support stress, and lining stress, and provide feedback to the design for guiding on-site construction.

The Significance of Tunnel Detection:

Tunnel detection, as one of the three core components of the New Austrian Tunneling Method (NATM), provides accurate and timely data for evaluating the feasibility of tunnel construction methods, the rationality of design parameters, and understanding the actual rock mass grade and deformation characteristics of tunnel construction. It is crucial in determining the timing of the construction of the secondary lining. Therefore, it is an essential means to ensure the success of tunnel construction. The primary tasks of tunnel monitoring and measurement should focus on enhancing safety, correcting designs, guiding construction, accumulating construction experience, and promptly providing analytical data to contractors, supervisors, designers, and owners through on-site analysis and processing of measured data.