Numerical Analysis of Heave Reduction Using EPS Geofoam Inclusions

Abstract

Expansive soils have a destructive influence on civil engineering structures; mainly the light loaded structures over the world. This damage takes place because the swelling soils undergo significant changes in volume and strength as a result of changes in moisture content. Expansive soils can swell or shrink when their water content increase or decrease depending mainly on the kind of clay minerals present in the soil formation. The variation of soil moisture content may be developed from many sources such as gardening wetting, lawn, pipe leaky, and climate changes. Therefore, the design of the structural foundation on this problematic soil needs to the knowledge of the behavior and stress-related deformability of the soil, also the geologic conditions. The prediction of the behavior of expansive, unsaturated soils should deal with many issues, that included soil properties characterization and a computing tool that can model the non-linear nature of expansive soils. Many methods can be used for the prediction of the swell/shrink behavior of expansive soil with different degrees of precision. Due to the difficulties of predicting the swell/shrink behavior of unsaturated soil, the numerical model considered the most common method for solving the equation of water seepage and soil deformation. Several treatment methods can be used for controlling the swell/shrink behavior of expansive soil such as soil replacement, moisture control, thermal methods, and surcharge loading. However, these methods have their limitations concerning costs and their effectiveness. Among the diverse treatment techniques, EPS geofoam can be used to mitigate the swelling of expansive soils and to reduce the structural straining actions that result from the ground heave. Materials and Methods: The EPS, as a soft soil inclusion, allows the expansive soil to swell. As such, structures on expansive soil may be designed with the aid of EPS to withstand only a small value of the swelling forces that may be induced by ground heaving under a constrained condition or a small part of the ground heave as the volume change is diverted away from the foundations. The essential aim of this paper is to present a tool for estimating, predicting, and mitigating the ground heave that associated with expansive soils. Moreover, study the impact of using EPS geofoam piles to minimize and reduce the effect of the heave potential associated with unsaturated, expansive soils on the structure foundations. Results: Numerical modeling of the behavior of expansive soil considered a powerful computing tool for estimating the volume change problems of structures rested on expansive soils. EPS geofoam as a compressible inclusion material has a significant effect on the matric suction distribution of unsaturated, expansive soils, and the decreasing of the soil heave. Conclusion: Numerical analysis shows that there is a reduction in the vertical swelling of soil with the inclusion of EPS geofoam. Also, with the increase in EPS dimensions, there is a significant reduction in the soil heave.