GPC Soil _Geocomposite (Soil Geocomposite)
Geocomposite is made of a layer of Geotextile reinforced with polystyrene yarn with high tensile strenght and low strain. This product is multi-functional including filtration, draining splitting and is widely used in road construction, railway tracks improving fine aggregate soils, and increasing the bearing capacity of unstable and swampy subgrades.
Application
The most important application of these products is to increase the bearing capacity of loose bed soil such as salty ground, sludge, crops, as well as the geobag fabrication for coastal protection. For coastal protection, while providing the required tensile strength against the waves, geocomposite layer of geobag lets the water flow pass through and prevents the escape of sand particles. Therefore, geocomposite provides high standard mechanical specifications for geobags fabrication.
In addition to the applications mentioned, the use of soil geocomposite in oil projects, especially the construction of storage tanks, is very significant. The installation process is straightforward and increases the speed of construction.
Slope instability caused by rain is the reason of many financial and life losses all around the world. This problem is more catastrophic in low permeable soils that cannot drain the rain water. Using soil geocomposite not only reinforces the slope, but also makes it more safe and stable by draining the rain water and thereby reducing the pore pressure.
Researches
Many researchers like Zorenberg (1994), Christopher (1998), Koerner (2001), Raisinghani (2010) have recommended highly permeable unwoven geotextile for effective drainage of in soil slopes. Also, Christopher (1998) and O’Kelly (2008) recommended use of geocomposite in reinforced soil slopes as a solution for reducing pore water pressure and improving the mechanical characteristics of slope which will increase stability and safety factor. Mitchell (1995) claimed that in case of proper design and execution of this product in slopes there will be no need for drainage system.
Newest studies
In 2015 a 63-degree steep slope with the height of 7.5 m was studied with and without layers of geocomposite material to study the applicability of soil geocomposite in stabilizing slopes made of low permeable soil in highly rainy regions. In case of acceptable performance, it would make the low permeable soil in site useable. The results of numerical modelling in SEEP/W showed that using 9 layers of soil geocomposite will reduce pore water pressure by 80 percent. The layer closer to the toe were more effective in pore water pressure reduction. After that, layer at the top and finally the layers at the middle were more effective in draining water.
In the study by David Carlos et al, it was shown that the mechanical characteristics of fine graded soil will be improved by using geocomposite. The amount of this improvement depends on the number of layers, their strength and their distance. Putting these layers in the sand will improve stress strain curve by limiting the lateral movements of the sand particles. In high strain levels the increase in the number of layers has more influence on improving the structural performance of the slope.