The value of basal reinforcement platforms
Whenever construction is carried out upon soft or unstable ground, there is the possibility of settlement. This can include geological effects caused by subsidence, sink holes and solution features as well as man-made effects, such as mining voids.
Differential settlement can be controlled by the construction of a basal platform to spread the loading upon the ground. In extreme circumstances, this platform can also be supported upon piles, for example within embankments supporting infrastructure. Whenever there are large increases in overburden on native ground, there is the potential of differential settlement or collapse. Within mining works, stockpiled materials or heap leach pads impose great surcharges upon the ground. Basal reinforcement helps to reduce differential settlement.
Spreading the load. The performance of this platform can be enhanced by the use of high strength geosynthetic geogrids such as our Paralink® with strengths up to 1350kN/m. These grids absorb, spread, span or dissipate the applied loads vertically downwards into the ground, or into the piles. Furthermore, by increasing the capability of the soil to “span” or “arch”, a high strength geosynthetic can enable the pile spacing to be increased.
Maccaferri geosynthetic solutions
Geogrids and geotextiles are often used in areas where mining subsidence is expected, or in areas where natural voids and solution features can occur. The geosynthetic is placed over the area of concern, so that in the event of the ground beneath collapsing, the geogrid or geotextile will span this void, supporting the ground above. Paralink® has been used for over 30 years for these reinforcement applications. In short-medium term applications, MacTex® W woven geosynthetics are also a useful consideration.
Solutions to ground water challenges
Moisture laden ground beneath a platform or an embankment can also cause settlement problems. As the pore water within the soil dissipates, it settles. Geosynthetics can assist here as well, whether by separating foundation materials with different technical characteristics, or in accelerating the consolidation of the soil. Strips of MacDrain® drainage geocomposites, installed vertically deep into the soil, can also be used to drain saturated cohesive foundations, accelerating the consolidation process. This has proven to be successful at reducing liquefaction during earthquakes.
More than just a product supplier. Although the solutions seem straightforward, this is the beauty of good engineering; the design of such interventions requires experience and a deep understanding of the performance of geosynthetics, not merely a product supplier or distributor. As a manufacturer, designer and supplier of these solutions, we are well positioned to understand and fulfil the technical needs of the client, optimising the solution, design and product; it is the combination of products and the performance of the whole system that is of paramount importance.