چكيده به لاتين
Abstract:
Due to the procedure of increasing in axial load and speed on the existing railway tracks, need of improvement will be felt over the embankment. In this regard, one of the techniques is the use of geocell in the process of upgrading railway tracks. Therefore determination of the number of geocell’s layers and alignment of their positions has a key role in this issue. Since influence of the number of layers and geocell’s specifications on stability control and railway embankments’ settlement are not specifically discussed in the technical literature, In this paper, by construction and loading of six embankments with 10 m height in Laboratory & numerical scale of 1:20, the influence of the number of geocell’s layers with aperture size of 5 x 5 cm and height of 5 cm is studied on the stability of railway embankments. After applying an increasing monotonic load over embankment’s crown until failure, the results showed that the bearing capacity and control Settlement of embankments was proportional to the number of geocell layers, as this process would increase until the four layers geocell, rather than decreased in the fifth layers. Bearing & settlement with four layers of geocell than embankment without any geocell had an increasing of 38.6 % and a decreasing of 37 % over embankment’s crown, respectively. In order to complete and develop the laboratory activity, numerical models were constructed in accordance with the laboratory models and sensitivity analysis was carried out on the cohesion & modulus of elasticity of embankment, modulus of elasticity of geocell, & perpendicular dimension to the plane of embankment. The results of numerical modeling was in accordance with the laboratory models and the maximum bearing capacity was obtained for fourth layers with 68.66 % increase than without any geocell.
Keywords: Geocell – reinforced embankments, Railway Embankment, Stability of Embankments, Settlement Control, Bearing Increase, Laboratory Model, Numerical Model.
