مهندسی عمران شریف (Feb 2016)
تحلیل عددی خاکریزهای راه مسلح به ژئوسل و بررسی پارامترهای مؤثر در عملکرد سیستم تسلیح با ژئوسل
Abstract
The use of reinforced soil has been considered since long ago. Due to the improvement in technology, different kinds of reinforcement, including geosynthetic and steel types, have emerged. Geocells, as a special type of geosynthetic, have recently been used for soil improvement. Their three dimensional geometry causes extreme lateral confinement for infill soil. This phenomenon leads to increased soil deformability and strength properties. The geocell reinforcement system is in the process of practical development due to its several advantages.Based on literature reviews in this field, theories and design methods are far behind applications in the field, especially roadway applications, due to a ack f nderstanding of their mechanisms and influencing factors.There are rather extensive laboratory studies in the field of geocell reinforcement, but because of its complexity, numerical modeling of geocell reinforcement has \ rarely been performed and most \ numerical studies are \ based on equivalent \ composite models for \ representing the \ strength and stiffness of geocell confined soil. In a composite model, the geocell reinforced soil is replaced with a soil with higher parameters. These parameters are selected based on limited test results performed on geocell reinforced soil. Therefore, generalizing them to other kinds of soil could be accompanied by further errors.In this numerical study, geocell and soil were simulated separately in 3D. Hence, this numerical modeling has no composite assumptions and errors. Also, all key behaviors of the geocell were included completely.In this paper, geocell reinforced road embankments are simulated using the Finite Difference Method (FDM) of FLAC3D. Geocell was simulated using geogrid structural elements, and the elastic-perfectly plastic Mohr-Coulomb model was used for modeling the behavior of soil. In order to verify the modeling, results were compared with the results of a laboratory test, and, then, different factors influencing reinforced embankment performance, including soil properties and the placement of geocell layers, were investigated.
