Reinforced soft soil by CSV with/without polypropylene fiber: experimental and numerical analysis

Abstract

Columns of mixed soil-sand-cement (CSV) is one of the most unused methods for reinforcing soils. To this end, in this paper, consolidated drained triaxial compression tests were carried out to investigate the effectiveness of CSV to reinforce the soft soil using varied combinations of CSV materials. Some of the tests were unsuccessful which can be labelled to the high quantity of cement. For this reason, an analysis with the design of experiments is established as an alternative method to estimate the equations for the sake of determining the results of the failed tests. Then, a numerical analysis using PLAXIS 3D has been used for studying the behaviour of soils reinforced by CSV under the embankment. Furthermore, a validation of the results with the analytic method has been properly presented. The experimental results have indicated that the efficiency of the reinforcement of the soft soil by CSV provides satisfying results, namely the less quantity of soft soil on CSV materials (with/without polypropylene fiber) the better the deviatoric stress, axial strain, effective cohesion, effective friction angle, and modulus of elasticity. Additionally, adding polypropylene fiber to CSV materials enhances the obtained results. Based on the numerical results, the reinforcement by CSV has noticeably reduced the displacements and improved security factors.