STUDY OF GEOSYNTHETIC EFFICIENCY FOR SLOPE STABILIZATION AND EROSION CONTROL

   Abstract:
      The slope stabilization and soil conservation with geosynthetic materials in the Quaternary alluvial sediments of Chandab region in southeast of Tehran was studied.
   The objective was to study the efficiency of geosynthetic materials in technical and economical aspects for high slope stabilization and decrease of soil erosion. The results could be applied for stabilization of slopes next to dam reservoirs or trenches resulted by road construction. A total of 24 plots with three repetitions with dimension of 12 x 2 meters on the slope of 85% and 110% were established. After each event of rainfall the runoff and sediments in each treatment were collected and the rates of sedimentation were measured. A total of 8 events resulted runoff and sedimentation. The data were analyzed with the Statles statistical program. The results showed in both slope types: a) in the 110% slope the erosion was much more than the 85% slope b) the treatment plots which were stabilized with geosynthetics indicated a lesser to no erosion. The computation results show that the lands with 110% slope have the erosion rate of 24.07 kg/ha. /yr if stabilized with geosynthetics, and 1218.9 kg/ha./yr if not stabilized. For the land with the slope of 85% the above rates are 1.5 kg/ha./yr and 135.25 kg/ha./yr respectively. Geosynthetics are made of polypropylene resistant materials. Because of low price and not necessity to complicated installation equipments, these materials are more economical and reliable them the other less than stabilization methods. The cost of Geosynthetics are less than 1/10 of the other materials, which they have no deleterious environmental effects.
  
   Key words: Geosynthetics, slope stability, Geosynthetics, Soil conservation, Erosion control, Iran