The Early Warning Signs of Surface Mine Subsidence
Malfunctioning machinery may be a warning sign for subsidence issues on mine sites, according to ground engineering specialist Mainmark. Often overlooked yet easy to address, subsidence can cause costly downtime and production bottlenecks if not identified early.
“Minor variances in ground level caused by subsidence can have a significant and costly impact on the smooth running of mine site machinery. Machinery malfunction is often attributed to poor quality or shoddy equipment when in fact, the problem may be a result of misaligned parts caused by ground subsidence,” said Tom Bailey from Mainmark.
Subsidence refers to the gradual caving in or sinking of an area of land. The most common causes of subsidence on a surface mine include drainage issues (caused by broken pipework or gradient that inhibits surface water run-off), poor compacted fill and mechanical vibrations which wear down the ground.
Subsidence causes machinery parts to change configuration, placing unnecessary stress on equipment and conveyor belts. Early signs of machinery misalignment:
· Unusual noise from the machinery
· Abnormal wear and tear, particularly on conveyor belts due to additional impact
· Excessive wear on machinery paths and bases, as a result of excessive vibrations that cause them to sink.
“Sustained over a period of time, this may cause the equipment to break down. The result is expensive repair and maintenance, decreased productivity and, in some cases, safety risks,” said Bailey.
Addressing subsidence before machinery fails is recommended for minimising the costs of downtime, and with modern ground engineering techniques, can be easier and quicker than many anticipate.
“Resin injection technology, such as Mainmark’s Uretek solution, is a proven, convenient, efficient and cost-effective alternative to traditional ground support techniques, such as underpinning. This method injects resin into fractured, broken or unstable rock and soils at high pressure to consolidate and re-stabilise the ground,” said Bailey.
Fast-set resin injection can be applied in-situ with minimal interruption to site operations. Depending on the scope of work, a project may be completed in a matter of days and performed outside of programmed maintenance shutdown periods allowing for flexible scheduling.
Mainmark offers a full range of polymeric and cementitious injection products for ground stabilisation and void filling in surface mines, including its patented Uretek resin injection solutions. A range of resins are available, including polyurethane, urea silicate, phenolic and amino-plastic resins. Mainmark holds required government and industry licenses, and its Civil and Mining division is ISO 9001 certified.
Mainmark methods strengthen and stabilise the ground with zero negative impact on the environment. These specialist techniques deliver optimum results and projects can often be completed while site operations continue. Non-invasive methods mean no excavation is required, minimising mess and hazards.
Case study: re-levelling a stacker crane rail at a Queensland coal mine
A Queensland coal mine recently appointed Mainmark to re-level a rail-mounted reclaimer. One of the rail’s footing beams had sunk, causing the crane to malfunction and limiting access to coal stocks.
Due to leaking water pipes, the rail footing deflected under load, causing the slab joint to sink. Mainmark’s expanding structural resin, Uretek, was injected under the rail footing beam to re-support and re-level it. The engineered resins combine chemically on entering the ground. The process is monitored by laser level to maintain control and deliver a precise result.
In just three days, Mainmark re-leveled and re-supported the crane rail and supporting beam, facilitating access to a significant stock of export coal.
To learn more, visit www.mainmark.com or call 1800 623 312.
Jessica Fell or Simone Esamie at Write Away Communication + Events
Ph: 02 9978 1400 or Email: firstname.lastname@example.org or email@example.com
Mainmark provides a range of specialist ground engineering and asset preservation solutions for commercial, industrial, civil infrastructure and mining sectors. Committed to excellence, Mainmark’s state-of-the-art solutions are backed by more than 20 years of engineering expertise. Mainmark has 15 sites across Australia, New Zealand, Thailand and Japan.
Mainmark products and services include solutions for ground stabilisation, void filling, stopping water ingress, raising and levelling on-ground and in-ground structures, fixing anchors into rock faces and embankments, and other related ground-engineering processes. The Mainmark Group consists of Mainmark Ground Engineering, Mainmark Civil and Mining and other engineering businesses.