Soil stabilisation is the process of eliminating voids, cracks and uneven soil and embankment levels where erosion, settlement or extreme wear may occur.
These conditions can be further accentuated by the various on-site operational activities which can lead to fluctuating soil conditions and configurations that can then have undesirable implications to both man and machine on the mine site
From a geohydrological point of view, the aim of soil stabilisation is to improve the weight bearing capabilities and performance of soils, sands, and other ground conditions.
On mine sites this requirement typically relates to the strengthening of road surfaces and access-ways where mining machinery and equipment is being regularly transported and/or stored.
Across Australia’s many and diverse mining environments, the main ground stability issues revolve around subsidence and stability, which are of particular concern when we are talking about soft soils.
The primary aim of soft soil strengthening in and around mine sites is designed to lead to:
• An increase in the stability of embankments
• An increase in the load bearing capacity of the soil
• A reduction in the active load stresses on retaining walls
• The prevention of liquefaction and other geohydrological problems
• An improvement in the deformation properties of the soft soil in order to reduce settlement, reduce the time for settlements, and to reduce horizontal displacement
Soil stabilisation also leads to an increase in the dynamic stiffness of the soft soil, which in turn reduces the vibrations to the surroundings and improves the dynamic performance of the substrate under normal geological conditions.
For other applications such as mine rehabilitation, the use of soil stabilisation technology helps overall ground remediation by creating an environmental barrier, stabilising the contaminated ground and creating an effective geohydrological barrier.
A number of stabilisation technologies and methods have been used over the last two decades, however in more recent years a number of companies have developed polymer cell matrix structures that provide direct mechanical stabilisation of the soil.
One new example is the GEOHEX™ erosion control system, which is engineered to prevent soil subsidence, promote ground and turf stabilisation, enabling maximum use of land, reduce surface water runoff and increased water conservation by the use of direct mechanical soil stabilisation.
This lightweight, long lasting and innovative soil retention system has been specifically engineered to be laid in any weather with minimum ground preparation and with virtually no training whatsoever.
Laboratory tested to withstand a maximum load bearing capacity of 720 tonnes per square metre when filled with soil, the GEOHEX™ erosion control system can be used in a range of mining applications including those that require the stabilisation of roads on mining sites as well as drainage stabilisation in hardstands, haul roads and truck parking areas.
According to the makers of the GEOHEX™ erosion control system, A Plus Plastics, when laid flat, two lightweight pieces are required to make one square metre and with its hexagonal cell-like design, the GEOHEX™ erosion control system is engineered to provide a very strong ground reinforcement system.
Due to its soft soil binding capabilities, the GEOHEX™ erosion control system also provides a number of other advantages including dust suppression – an important benefit in country like Australia, where mining sites invariably also contain of fine, clay-like particles on the top soil.
According to the company, “While the GEOHEX™ erosion control system is engineered to have a range of ubiquitous soil stabilisation applications, its inherent high load bearing capacity and strong and rigid cell like structure means it has a variety of mining applications across the country.”