INVESTIGATION ABOUT SHEAR BEHAVIOR OF SAND REINFORCED WITH GEOTEXTILE WITH EMPHASIS ON SHEAR ZONE

Investigation of the effect of angle and geotextile position on the sand resistance parameters is the aim of this experiment. The behaviors of the tested samples were analyzed by the direct shear tests results and charts derived from it. In this study, three positions, including vertical, horizontal and oblique, were studied. Each of these items also has other arrangements. In total, 17 different arrangements were tested under three overload stresses. The type of soil is have lower initial shear sand. The results show that soil reinforced horizontal arrangements stiffness. Also, they have softer behavior. In vertical arrangements, the shear strength increases with increasing number of layers. Shear strength in oblique arrangement with two layers is greater than the vertical arrangement with two layers. For example, for stress of 2 kg per square centimeter, in arrangement with two-layer vertical and double-layer, there are oblique 23 and 33 percent increases in resistance. In oblique arrangement, the less the position angle relative to the horizon is, the more the shear strength will be. Using reinforcement elements in improving geotechnical properties of soil has been considered by a human for many years. In recent years, many improvements have been made in the field of improving poor soils and reinforcing them. Soil reinforcement has been used as an effective method to improve the soil layers in order to increase the bearing capacity and reduce the settlement. In oblique arrangement, the results showed that if the direction of moving geotextile is in line with that of cutting, then we can observe an increase in the rate of resistance; if the direction of moving is in opposite direction with shearing direction, then we can observe a decrease in the rate of resistance. The results of vertical arrangement showed that by increasing geotextile layers, the rate of resistance increased. The results of the test showed that in horizontal arrangement, the rate of flexibility decreased and not significant difference in the rate of resistance was seen. The results of the study on different samples showed that using geotextile almost in all the conditions caused an increase in the rate of flexibility and resistance.