Numerical analysis of geosynthetic encased sand columns affected by changing the physical dimensions of columns

Enayatallah Najari¹ Ali Noorzad² Mehdi Siavoshnia³

1) Department of Civil, Faculty of Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran, Islamic Republic of (Iauctb), Email:
2) Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Hakimieh, Tehran, Iran, Islamic Republic of , Email: a_
3) Department of Civil, Faculty of Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran, Islamic Republic of (Iauctb) , Email:

Publication : 2nd.International Conference on Civil Engineering, Architecture and Urban Design 31 Aug. 2017, Kasem Bundit University , Bangkok , Thailand(2iccacs.com)
Abstract :
Using stone columns technique is a method of improving weak soil such as soft clay, silt and loose sand that have shown good performance and compatibility with the environment. Columns create a composite material with a lower overall compressibility and greater shear strength than the primitive soil. In this study, it’s tried to find the optimum parameter for reinforcing weak soil. This optimum parameters in addition to creating good resistance conditions to poor soil in terms of horizontal displacement and vertical settlement, are more efficient than other models with respect to economical aspect. Variable parameters examined in this study consisted of length and diameter of sand columns under surcharge load of 50 kPa on rigid foundation. three-dimensional models analyzed with Abaqus (14-4-6) software. Evaluating the results of models, in this study it’s illustrated that encased sand columns have improved settlement and bulging in clay soil for approximately 66% and 62%, respectively and the effective length of columns has been determined. It can be concluded that geosynthetic encasements have a good effect on improving the performance of group sand columns and can be used with a few number of columns with shorter diameters by encasing them together with the optimum material that have appropriate stiffness.
Keywords : Sand columns Geosynthetic Settlement 3D analysis