GEOSSYNTETICS – A NEW STUDY ON THE BEHAVIOUR OF SOIL-GEOTEXTILE SYSTEMS UNDER GRADIENT RATIO ANALISYS.
News Gradient Ratio Analisys realized with new GR-PVC apparatus showed that the shape of these equipaments has influenced in the saturation conditions of the soil-geotextile samples.
The gradient ratio test is used to study the soil-geotextile compability in filtrations applications. The behavior of soil-geotextile tests is reported for non-woven geotextiles under unidirecional flows direction. A new apparatus was developed to perform filtration tests. It was conducted with different soils types and nonwoven geotextiles in order to evaluate the clogging potential and retention capacity under severe combinations. The evaluation is based in observed variations of water head and permeability in the composite soil-geotextile. Time and hidraulic gradient specifics were measured, accordant to ASTM D 5101. The results shows that soil has influenced the filtration characteristics in geotextiles. Permeability of soil-geotextiles allways have to occur by water head. More studies will be done to avaliate the quality of the samples, the durability and homogeneous fiber distribuition during life-time of this geossyntetic for this situation. Finalizing, the new equipament made by PVC material is better than the one presented and recommended by ASTM D 5101. The saturations conditions are more easier and quick to complete with the PVC apparatus than in the iron one. The cost to fabrication is too cheap when compared with traditionals appaatus because it is formed by PVC tubes used in the civil construction engineering. The complete paper was sended to the Soils and Rocks Magazine (Brazil) (2007).
Marcelo Ferreira dos Santos
is a Technical Consultant in Civil Engineering. He's studying a Master Course in Quality Management at Salvador University (UNIFACS).