**3. Results and discussion**

### **3.1. Factors affecting the short-term compressive behavior-**

**Figures 4–10** show the results of correlation between various manufacturing parameters and the compressive strength. The relationship between all of these manufacturing parameters of geonet and the compressive strength were not well defined through analysis of experimental values and it is assessed that the compressive strength of a geonet cannot be related to such as weight, geometrical properties, crystallinity, rib mechanical properties, etc. Only, compressive strength is determined by a combination of these factors and thus has to be controlled as any other material constant of a geonet.

**Figure 4.** Plot of compressive strength vs. thickness.

**Figure 5.** Plot of compressive strength vs. mass per unit area.

**Figure 6.** Plot of compressive strength vs. strand intersection angle.

**Figure 7.** Plot of compressive strength vs. crystallinity: (a) at intersection and (b) at strand.

Analysis of Porous Behaviors by Water Flow Property of Geonets by Theoretical Simulation 65 http://dx.doi.org/10.5772/intechopen.85951

**Figure 8.** Plot of compressive strength vs. strand strength.

**Figure 9.** Plot of compressive strength vs. junction strength.

To determine the compressive strength, the strand slope associated with the range of roll-over may not affect the confining strength, since the confining strength measurement time is after the start or end point of the roll-over (**Figure 11**). In **Figure 11**, the roll-over distance of a rectangular geonet strand is longer than that of a circular stranded geonet. Additional evidence for the relationship between the strand cross-sectional shape and the rollover behavior to support this can be seen by comparing the shape of the compressive strength-strain curve of the geonet shown in **Figure 12**.

The cylindrical type exhibits a very stiff behavior even after the end of the roll-over and has very short roll-over range compare to the bi-planar which has very long roll-over region. By defining the factor that affects to the short-term compressive strength behavior of the bi-planar geonet, it should be determined that before the determining point of compressive

**Figure 10.** Plot of compressive strength vs. strand inclination.

**Figure 11.** Relationship between strand cross sectional shape and roll-over range.

strength. Also, all of the manufacturing parameters can affect the transmissivity of the geonet and strand inclination and strand cross-sectional shape will affect the roll-over phenomenon mainly.

Therefore, it is concluded that if the cross-sectional shape of the strand is close to the circle, the roll-over region could be shortened dramatically and this advantage will contribute to the advance the long-term flow capacity of the geonet.-

Analysis of Porous Behaviors by Water Flow Property of Geonets by Theoretical Simulation 67 http://dx.doi.org/10.5772/intechopen.85951

**Figure 12.** Plot of compressive strength-strain curves of various geonet samples.

**Figure 13.** Plot of compressive behavior curves according to various deformation rates at 23°C test temperature: (a) bi-planar- and (b) tri-planar.
