Demolition of structures
Creating reinforced structures, tracks and enforcing lighting in tunnelling requires demolition of pre-existing underground areas through explosives. These heavy-duty industrial processes create large volumes of respirable dust due to the destroying of natural materials such as rock and sand, presenting major risk to workers health.
Use of TBMs
Alongside demolition to create tunnels, Tunnel Boring Machines (TBM) are also used. The sheer velocity and speed which TBM’s operate at often generates high levels of respirable dust, and due to conditions of the environment underground, this dust cannot always be properly controlled, posing risk when workers enter the tunnel.
Shotcreting onto surfaces
A construction technique where concrete or mortar is sprayed onto a surface for reinforcement, shotcreting involves large volumes of dust throughout the tunnel construction. The shotcreting process causes splash-back of dried concrete, which is ground down and creates dust, putting workers on the job at risk of health issues.
Rock bolting
It’s not just the creation of tunnels that creates high levels of dust. Maintenance and support processes such as rock bolting in tunnelling also creates airborne respirable dust. By drilling directly into the rock and installing bolts to make the structure more stable, respirable dust is generated from the rock, exposing all underground workers.
Transport of materials
Rocks and stones often need transporting from one area of a tunnel to another for enforcing areas. With the brittle nature of these materials and the rugged environment, these materials easily break down. As well as this, the large industrial vehicles underground kick up sand and dirt, creating large volumes of respirable dust.
