Tunnel monitoring

1.Tunnel monitoring background

In recent years, with the rapid development of my country's economic construction and cities, and the rapid development of infrastructure construction such as highways, high-speed railways, and subways, my country's tunnel construction work has entered a period of rapid development, and various tunnel accidents have occurred frequently. The soil engineering geology and hydrogeology of the tunnel are complex and changeable. Existing tunnels are affected by geological conditions deterioration, fire, structural damage, degradation and instability, natural disasters, etc., and often suffer from tunnel vault cracks, side wall cracks, lining damage, tunnel leakage, tunnel frost damage, large deformation of surrounding rocks and other diseases. How to diagnose the health of active tunnels or tunnels during construction and prevent and control diseases and disasters is extremely important.

2. Tunnel monitoring system overview

The geological conditions of tunnel surrounding rocks are complex and the construction environment is harsh. Traditional manual detection methods are difficult to fully guarantee tunnel safety. Our tunnel online monitoring system provides targeted monitoring solutions for the key and difficult issues in tunnel monitoring throughout its life cycle, ensuring the safety of tunnel construction and operation.

3. Tunnel monitoring main monitoring content

1. Deformation monitoring: vault settlement and convergence monitoring, and internal displacement of surrounding rock;

2. Stress monitoring: anchor axial force, primary support stress, secondary lining stress, contact pressure between surrounding rock and primary support, contact pressure between primary support and secondary lining, and steel arch stress;

3. Groundwater monitoring: water pressure;

4. Environmental monitoring: temperature, humidity, smoke;

5. Existing defects monitoring: cracks;

6. Risk sources:

①Building monitoring: uneven settlement, tilt, cracks;

②Surface monitoring: uneven settlement;

③Tunnel entrance slope monitoring: surface displacement, internal displacement, rainfall, and soil moisture content.

IV. Tunnel monitoring project list

5. Tunnel monitoring basis

Technical Specifications for Highway Tunnel Construction JTG/T 3660-2020

Technical Specifications for Highway Tunnel Construction Monitoring (Draft for Comments)

Technical Specifications for Urban Tunnel Maintenance DB41∕T 1271-2016

Railway Tunnel Monitoring and Measurement Technical Specifications Q/CR9218-2015

Technical Specifications for Highway Tunnel Maintenance JTG H12-2015

Technical Specifications for Highway Tunnel Construction JTGF60-2009

Railway Tunnel Monitoring and Measurement Technical Specifications TB10121-2007

6. Tunnel monitoring implementation functions

1. Full life cycle monitoring: During the construction period, corresponding sensor equipment is arranged inside the tunnel or outside the secondary lining to automatically monitor tunnel deformation, stress, etc. online, so as to achieve full life cycle monitoring of the tunnel. GIS+BIM is used for comprehensive visualization of the model to understand the status of the tunnel throughout its life cycle and provide a decision-making basis for management;

2. Automatic report push: In addition to real-time display of monitoring results, the system will automatically generate corresponding daily reports, which can be downloaded with one click. Once the data exceeds the threshold, it can issue an early warning and notify relevant units to take corresponding measures in a timely manner;

3. Graded warning: Set different warning levels as required. When data is abnormal, the warning information will be automatically triggered according to the settings, including platform push, SMS and email notifications to the corresponding person;

4. Accumulate tunnel status data: Provide necessary decision-making basis for long-term operation, maintenance, repair and reinforcement of tunnels, and provide basis for safety status assessment of tunnels after emergencies. At the same time, AI algorithms are used to predict the structural response and development of bridges in the future.

5. Provide reference basis: verify the design and construction theory and construction technology of the tunnel, so as to improve the relevant design and construction technical regulations and ensure the safe use of the tunnel.