Behavior of Embankments Constructed on Soft Soil Deposits Reinforced with Rigid Inclusions

Large settlement associated with the construction of embankments on soft soil deposits is a challenging geotechnical problem that needs a special treatment. Reinforcing the embankments utilizing geosynthetics is an effective technique used to reduce the differential settlement, while the total settlement is unchanged. A more efficient technique is utilizing a combination between soft soil reinforcement using piles or rigid inclusions, thus increasing the equivalent stiffness of the entire soft soil stratum, and a load transfer layer reinforced by one or more layers of geosynthetics on top of the inclusions' head, in order to improve the load distribution process between the rigid elements. In this paper, the behavior of soft soil deposits reinforced with rigid inclusions is studied using three-dimensional finite element analysis, utilizing the "PLAXIS 3D 2020" software. Verification of the adopted modeling procedures is performed by the back analysis of a well-documented case study of a physical laboratory scaled model. Results of the numerical model showed a good agreement with the laboratory measurements in terms of both the settlement and load distribution aspects. Furthermore, results of both the developed numerical model and selected performed numerical analyses, from the literature, for the same case study, were compared showing better efficiency of the developed model compared to others and more consistency with the real behavior of the laboratory model. The verified model confirmed the efficiency of increasing the friction angle of the embankment on the load transfer mechanism between the rigid inclusions, and hence decreasing the resultant settlement.