Eliminating Hazards in Underground Coal Mine Development Roads with Composite Matting
This was originally published online by JWA Oilfield Supplies.
Underground coal project specialists Ipsum Mining took an innovative approach to managing development roads and mitigating roadway deterioration with the integration of DURA-BASE Composite Mats into the coal cutting sequence.
Chain Valley Colliery, Mannering Park NSW (Delta Coal)
A common cause of fatalities and major injuries in underground coal mining is from shuttle car movements in development panels. The development process of underground roadway headings results in the deterioration of road conditions. The reduction in the strength of the roadway surface is caused by the use of heavy machinery, water use in the mining process and the repetitive traffic throughout the mine’s life.
The focus for this project was to protect the bootend approach roadway for the shuttle car operation. Here the combination of high traffic with clay floor and water mix from coal cutting creates the conditions for wet and pothole-riddled roads. This is hazardous for the shuttle cars with 4 wheel steering, increasing the risk to slew and slide towards the ribs causing crush injuries at pinch point areas.
36 meters of DURA-BASE Composite Roadway Mats supplied by JWA Oilfield Supplies were installed from the bootend inbye to cover the potential hazard zone.
- The modular bog mats are delivered underground in bundles of 10 with each mat weighing 454kg.
- The bootend approach area is back bladed with excess rib sprawl removed for a level base to install the mats on.
- The installation of the bog mats is quick and efficient. Rigging up the first mat using jib and Eimco, it was positioned inline with the bootend with the underlying lip facing inbye. Each mat is then installed and locked into position using 4 locking pins, with all 18 mats and 2 high-visibility ramps installed in a 90-minute timeframe.
The completed composite mining roadway with ramp access provides a stable surface for the shuttle car to approach the bootend with ease. The shuttle car wheels now have a solid platform to drive on and have eliminated the wheel ruts from the previous road conditions consisting of coal, clay and water slurry mixture.
The 105mm thick HDPE mats are non-permeable which puts a stop to the constant mixing. DURA-BASE mats are 4.27m in width which allows a surface area next to the rib of the 5.4m heading to set up an auger hole and pump to remove the now clean water from this area.
The uniform strength and distribution of the shuttle car weight on the roadway matting allows a level approach to the bootend. This can be guided by pinhole reflectors and road markers installed on the matting surface. A DURA-BASE wall berm can then be installed directly onto the matting to clearly mark a stop point for the positioning of the shuttle car arriving at the bootend, improving the efficiency of unloading onto the bootend and belt system.
At the bootend area, which is the main spillage point in the development panel process, the mining bog mats can be installed in the orientation (underlying lips facing away from the bootend) allowing the Load Haul Dump Loaders (LHDs) to muck out towards the bootend and remove any spillage.
In this development situation DURA-BASE has been used as a proactive measure in areas of poor ground, effectively reducing the risk of shuttle car incidents.
Feedback from Delta Coal project team
- "The use of DURA-BASE in soft floor conditions was paramount to the success of the development panel through these areas".
- "DURA-BASE is now an integral part of the development process sequence".
- Improved road conditions raising workplace safety and morale.
- Efficient travel times and production efficiencies – mine design guidelines state a flat uniform roadway increases production by 6%.
- Lower exposure to walkway hazards – Shuttle car cables now sit on roadway matting, which reduces risk of humans tripping, rolling ankles and falling.
- Reduces musculoskeletal disorders – Level road surface lowers operators’ exposure to whole-body vibrations during transport
- Reduced operational and maintenance costs – reduced vibration to the shuttle cars lowers the stress on alternators and drive motors.
- Logistic agility - the operational benefit of using DURA-BASE Composite Mats is the ease and speed of installation. Provides teams with the ability to replace roadways or patch sections almost instantly compared to the waiting time of days or weeks from using concrete.
Thank you to Dylan Roberts for his contribution to the article. Ipsum Mining are JWA’s exclusive partners for underground coal projects. For more DURA-BASE applications, visit www.jwaoil.com.