Tunnel Safety Monitoring

一.Background

    Domestic infrastructure is expanding from the plains in the east to the west, and in the process of developing urban traffic from above ground to underground traffic, many tunnels need to be built every year. The terrain of tunnel construction is complex, and many safety accidents often occur. The safety accidents of tunnels mainly focus on dangerous accidents such as water ingress, gas leakage, toxic gas generation, and landslides.

二．Functional Requirements

    2.1 Overall functional requirements

     For the monitoring and communication of safety incidents such as water ingress, gas leakage, toxic gas, and vital signs, our company has developed a complete solution for tunnel safety accidents. This program includes wireless coverage, voice communication, voice alarm, dangerous gas monitoring, water level monitoring, soil moisture monitoring, and alarm platform. Its overall block diagram is as follows:

总体功能需求

 

    2.2 wireless transfer

    In most of the tunnels, there is no mobile communication network. Our company has developed a set of 400MHZ full wireless coverage technology for the special environment of the tunnel. In every corner of the tunnel, wireless walkie-talkies can be used to wirelessly collect tunnel environmental data.

 

    2.3 Tunnel gas monitoring

    The poisonous gas in the tunnel has always been the main source of danger in the construction. If the construction is improper, it is very easy to cause major safety accidents. The harmful gases in the tunnel mainly include methane, carbon monoxide, carbon dioxide, hydrogen sulfide and other gases.

   Our company has developed a variety of gas monitoring sensors for the composition of the tunnel gas. The gas parameters are as follows:

Gas Gas range Resolution Remark
Oxidation (o2)

0~30%VOL

0.1%VOL

 
Hydrogen Sulfide (h2s)

0~100ppm

1ppm

 
Carbon Monoxide (co)

0~500ppm

1ppm

 
Alkene Gas (ex)

0~100%LEL

1%LEL

 

 

 

 

 

   These kinds of sensors use the same casing, and only the front sensor probes are replaced with different sensors. The parameters of the finished products are as follows:

Project Parameter Remark
Explosion-proof Certification

Exd IICT6 GB

 
Waterproof Level

IP68

 
Signal Output Method 4~20MA, RS485 Signal Output

 
Pointer Power, fault, alarm three indicators

 
Signal Output One set of passive relay outputs

 
Data Accuracy Multi-point calibration + temperature compensation

 

 

    2.4 Tunnel flooding prevention

    In the process of tunnel construction, water ingress is also another major source of safety accidents. There are many reasons for flooding, but flooding accidents can be prevented. As long as accidents are prevented in advance, accidents can be prevented.

    For the tunnel flooding accident, our company monitors the soil moisture content and the tunnel water level. Using our company's soil moisture monitoring sensor, when it is found that the soil moisture content increases, it will alarm. At the same time, the water level of the tunnel is monitored. When the water level of the tunnel rises, an alarm is issued to prevent the occurrence of safety accidents.

    2.5Personnel activity track monitoring

   The light in the tunnel construction area is dark, and it is impossible to clearly see the movement trajectories of the personnel. The use of our company's personnel movement track sensor can monitor the movement direction, breathing, heartbeat and other life characteristics of people in the tunnel. When a safety accident occurs in the tunnel, this can be used as an important reference for search and rescue.