Main applications of geotextiles

High-modulus woven geotextiles FORTEX of GEOMATRIX are woven with fibers of the exclusive G5 Multifilament High-Tensile Polyester (PET), characterized by high mechanical and hydraulic performance. Their structure is defined by the weft insertion technique, which provides rapid stress response to soil deformations and stable hydraulic performance at any level of stress or confinement. Additionally, the geotextiles FORTEX They are characterized by:

• Have a high stress-strain ratio (high mechanical modulus, see Figure 1). The high modulus mentioned above creates a tensile component that, when incorporated into the granular material, increases the elastic recovery and load-bearing capacity of the granular substructure and prevents deformation of the foundation soil, thereby benefiting both the construction process and the pavement’s performance.

 

 

 

• Figurera 1. High Modulus of Elasticity of Polyester Geotextiles 

(From Typical properties of fibers. Batson. Designing with Geosynthetics. RM Koerner). 

PET: high-tenacity polyester, PP: polypropylene, HDPE: high-density polyethylene. 

High mechanical stability over time (low creep, see Figure 2).
This concept refers to the low yield or plastic deformation exhibited by geotextiles FORTEX over the long term compared to polypropylene (PP) geotextiles, which means that the resulting decrease in strength is minimal; consequently, the reinforcing function is maintained over time, thereby controlling future deformations of the structure.

                                                                                                                                                                                                        

Figure 2. Creep results for fibers made of different polymers. (Adapted from Koerner R.M., *Designing with Geosynthetics*)

 

• Guarantee its durability in the face of contact with naturally aggressive soils, due to the high molecular weight and carboxyl group of the G5 PET Multifilament. 
• Demonstrate stability in their hydraulic behavior under any stress or confinement conditions. Geotextiles FORTEX are manufactured using the weft insertion weaving technique, in which the horizontal and transverse fibers are arranged in two independent layers, interlaced with a third group of fibers that are inserted by adjusting the nodes, as shown in the following figure. Figure 3.
  In this way, the main fibers remain straight and ready to bear a load at the slightest deformation, while maintaining their position, ensuring that the pore area—or open area—does not change due to tension or confinement of the geotextile, thereby achieving stability in hydraulic performance. 

                                                                                   

• The resulting hydraulic behavior prevents the buildup of excess pore pressure, which can cause cushioning in the granular layer. From a mechanical standpoint, the elements that make up the material are completely straight, thereby providing rapid mechanical reinforcement that benefits both the performance of the embankment structure and the construction process, thus making a significant difference compared to woven geotextiles made of flat polypropylene tape.
•  When the geotextile is installed, it provides significant reinforcement, separation, and filtration.

 

Woven geotextiles FORTEX offer high modulus and high tensile strength, so that interaction between granular layers or between the subgrade and granular layers results in a significant increase in the soil's bearing capacity. The resulting reinforcement effect is due to soil improvement phenomena and the tensioned membrane effect (Perkins et al. Ishmeik 1997 a), which ensure a competent and high-performing structure.

 

 

BENEFITS OF FORTEX GEOTEXTILE 

Given these characteristics, the implementation of the soft soil reinforcement solution using geotextile FORTEX It mainly presents the following benefits: 

•  A substantial increase in the bearing capacity of the subgrade soil under saturated conditions to ensure the performance of the proposed structure during both the construction and service phases. 
• It allows for the creation of a work platform for the operation of construction equipment without exceeding the bearing capacity of the subgrade. 
• Monitor any deformations that may occur due to volumetric changes in the subgrade
• When the geotextile is installed, it provides significant reinforcement, separation, and filtration, thereby improving the structure's performance. 
• The resulting stress distribution allows the applied loads to be absorbed primarily by the upper layers, so that the subgrade soil experiences minimal deformation due to the low applied stresses. 
• Reinforcing the subbase improves the modulus ratio starting with the first layer of the structure, thereby enhancing the structure's performance and durability. 
• geotextiles FORTEX They provide long-term stability due to the low creep of the G5 polyester multifilament from which they are made, which further enhances their resistance to permanent deformation and critical conditions in the performance of subdrainage systems. 
• Reinforcing the subgrade significantly speeds up the construction process, as it prevents defects from occurring, thereby reducing cost overruns related to excavation and materials while also shortening construction timelines.
  

geotextiles FORTEX When interacting between granular layers or between the subgrade and the granular layers over a large area, they increase the soil’s bearing capacity while altering the distribution of stresses with depth. This effect is explained by the phenomena illustrated below: 

• Improved support capacity. 
• Stressed membrane effect (Perkins and Ishmeik1997a). 

 

Improved support capacity 

This mechanism results from the upward displacement of the failure envelope of the foundation system. The geotextile acts as a barrier that controls the lower surface of the failure envelope, confining it entirely to the upper soil layer, which offers greater shear strength than the subgrade (see Figure 4). 

 

 

Figure 4. Bearing capacity improvement effect. 

 

 

Tensed membrane effect 

This effect is based on the improved vertical stress distribution resulting from the tensile stress in a deformed membrane (see Figure 5). The deformation of the subgrade soil under the applied load causes the geotextile to be tensioned; the vertical component of this tension relieves the stresses imposed by the surcharge, thereby protecting the foundation soil. 

 

 

Figure 5. Tensed membrane effect

 

In addition to the above, when it comes into direct contact with the subgrade, it acts as a barrier between the subgrade material and the granular layers, preventing contamination through intrusion and/or direct contact, thereby ensuring the proper performance of each layer of material from the outset (see Figure 6). 

 

 

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