عنوان مقاله [English]
There are different methods to improve the technical characteristic of problematic soils. Stabilizing with lime and reinforcing by high tensile strength elements are among the improvement techniques.. The use of geosynthetics to improve the engineering properties of various types of soil is well accepted now. Most of the studies have been limited to coarse-grained soils and few studies has been done on the feasibility of geosynthetic reinforcement on cohesive soils. Due to the positive effects of adding lime to fine-grained soils and their reinforcement by geosynthetic, concurrent effects of these methods can develop the usage of fine-grained soils. In the current research, clay samples have been stabilized with 0, 2, 4 and 6 % of lime and reinforced with geosynthetic (geotextile and geogrid) and cured for 1 and 7 days and then subjected to direct shear test. To investigate the soil-geosynthetic interface parameters and reinforcement efficiency, the direct shear tests were done on reinforced samples with geotextile and two groups of reinforced samples with and without transverse members of geogrids. The test results reveal that stabilization with lime increases shear strength and it is also increased with curing time. The shear strength of reinforced samples is higher than that of unreinforced samples, and under the same normal stress the shear resistance of the soil reinforced by geogrid is higher than of that reinforced by geotextile. Under the same curing time, the highest shear strength and reinforcement efficiency is achieved in samples reinforced and stabilized with 4% of lime and they are also increased with increasing curing duration.