INVISIBLE DANGER IN TUNNELING: DUST CONTROL AND SAFETY GUIDE

INVISIBLE DANGER IN TUNNELING: DUST CONTROL AND SAFETY GUIDE

In tunnel projects, worker health is as much a priority as efficiency. Since shotcrete application is performed with high-pressure air, it rapidly increases the dust concentration in the environment. Combating this dust is not just a legal requirement, but a vital responsibility for human health.

1. The Invisible Threat of Tunnel Dust: Silicosis Microscopic quartz and cement dust mixed into the air during tunnel excavation and shotcrete penetration reach deep into the lungs through respiration. Long-term exposure to this dust can cause a serious and irreversible lung disease called "Silicosis." The fundamental way to deal with this risk is to control the dust at its source and apply the right engineering solutions.

2. Technical Methods and Machine Design in Dust Control To minimize the dust rate, the following technical standards should be targeted in machine design and application methodology:

• Wet System Shotcrete Technology: Compared to the dry system, wet system spraying reduces dust formation by 80%. Since the concrete is already in wet form, the amount of particles released into the air remains at a minimum level.

• Engineering and Sealing: Precise alignment in the sealing plates of the machines physically prevents dust leaks that may originate from the machine body.

• Closed System Chemical Transfer: Transferring chemicals in a closed system with dosing pumps minimizes the risk of direct contact of the operator with hazardous substances.

3. Common Application Errors in the Field A large portion of dust formation and work accidents stem from faulty application habits:

• Incorrect Nozzle Geometry: The operator not holding the nozzle at a 90-degree angle to the wall and at the ideal distance increases rebound and dust dispersion.

• Lack of Ventilation Planning: The capacity of the systems that blow fresh air into the tunnel and discharge the dirty air must be calculated according to the shotcrete operation.

• Chemical Contact Risks: Accelerating additives used for concrete setting can be irritating. Alkaline concrete splashing from the nozzle harming the operator's skin or eyes is a common safety vulnerability in the field.

4. Chemical Safety and Reaction Management Due to the aggressive nature of concrete additives, the following measures are vital during operation:

• Protective Barriers: Acid-resistant gloves and full-face masks must be used against alkaline concrete and chemicals.

• Dynamic Protection: Supplying chemicals to the machine via controlled and closed-circuit systems minimizes the possibility of environmental spread and contact.

5. Personal Protective Equipment (PPE) Standards Every personnel working in the tunnel site must be equipped with the following:

• FFP3 Type Dust Masks: High-protection masks that filter dangerous dust at the micron level.

• Antifog Goggles: Special protective glasses that do not fog up in the humid tunnel environment.

• Waterproof Work Clothes: Technical overalls that create a barrier against concrete and chemical leaks.

• Helmet and Earmuffs: Necessary for protection against noise and physical impacts.