Dust Control for Tunnel Construction

Tunnel Construction. Dust Challenges. 

Underground construction environments, especially those with limited airflow such as shafts, cross passages, and stations, require effective dust control and ventilation. Combining existing measures with adapted approaches helps to create more productive job sites and decreases exposure to contaminated air.

The inherent nature of tunnelling leads to disease-causing particles becoming airborne. Every step of the construction process, including excavation, shotcreting, material loading and transporting represents a health hazard to workers.

Dust causes further challenges when tunnelling, including reduced visibility, lost materials, lower productivity, and additional wear and tear on equipment.

Health and Safety. Driving the Demand for Dust Control. 

A critical aspect of any tunnel construction is ventilation design and dust control, so that workers exposure to fumes and dust are reduced to safe, acceptable levels.

The importance of dust control in recent years has increased with awareness regarding Respirable Crystalline Silica (RCS). Silica or silicon dioxide is a naturally occurring and widely abundant mineral that forms a major component of most rocks and soils. Crystalline silica dust is the biggest risk to construction workers after asbestos as dust particles can penetrate deep into the lungs. Heavy and prolonged exposure to RCS can lead to serious health problems for tunnel workers including lung cancer, silicosis, pulmonary disease, and kidney disease. Silicosis is the most common occupational lung disease worldwide. Silicosis usually follows exposure to RCS over many years, but extremely high exposures can cause acute silicosis more quickly. As a result of increased awareness, industries are becoming more regulated to help keep workers safe.

New health and safety regulations specifically relating to the control of respirable crystalline silica (RCS), have been introduced to bring it into line with asbestos. Many countries are now halving the workplace exposure limit (WEL) for RCS for an 8-hour time weighted average from 0.1mg/m³ to 0.05mg/m³.

Due to the high production volume and enclosed workspace, workers in underground operations have a higher risk of dust exposure. Management of dust within tunnel construction usually requires a hierarchy of control measures to be implemented including the use of dust scrubber (dust collector) and providing ventilation at the face through brattice wings or ducting.

Tunnel Ventilation and Dust Control. Holistic Planning.

Tunnel construction is a complex process that requires careful planning, specialised equipment and a skilled workforce. This is because tunnels are constructed using various methods depending on the type of rock or soil, the length and depth of the tunnel, and the purpose of the tunnel.  Without proper holistic planning, projects run the risk of out of sequence work.

Working out dig sequences and airflow requirements from the very beginning of a tunnel construction project has been proven to deliver the following benefits.

1. Reducing airborne particulates to create a safer environment for workers.
2. Reducing power consumption and costs – this can equate to multiple million $ savings.
3. Increase the speed of tunnel construction and further reduce costs and timescales by using more efficient excavation approaches.

Tunnel Construction Dust Control. Our Solutions.

New technology and innovative approaches to dust control have helped drive positive change and adherence with the new regulations and our experienced team of consultants and engineers can assist you in developing an obligation free ventilation and dust control plan tailored specifically for your project. Contact us today for more information!