Probabilistic Study on the Geotechnical Behavior of Fiber Reinforced Soil

Abstract

Expansive soils which are considered extremely problematic due to their potential to create swell and shrinkage related distresses. In order to satisfy the geotechnical requirements, these soils are fiber reinforced to sustain dynamic loads as a subgrade material. Polypropylene fiber materials when amended with soil medium, have proven functionality in the long run. Usually, a binder is required to ensure proper bonding between discrete/random fiber elements and the clay particulates. In the current study, lime is a proposed binder and its dosage is fixed at 6% satisfying initial lime consumption and optimum lime requirements. Two types of fiber materials (Fiber Cast® and Fiber Mesh®) at varying dosages (0.2, 0.4 and 0.6% by weight of soil) and having different lengths (6 and 12 mm) are considered for the present study and its inclusion effect on the hydraulic conductivity, unconfined compression strength behavior and California bearing ratio behavior has been studied. The focus of this paper is in determining the optimum fiber reinforcement parameters (fiber-type, length, dosage etc.) for the stabilization of selected expansive Al-Ghat soil. Probabilistic analysis has been performed to correlate the targeted properties with aspect parameters (i.e., dosage and length) for fiber reinforced soil. In addition to this, reliability analysis has been performed to examine the applicability of this fiber reinforced soil in Municipal Solid Waste (MSW) landfills for waste containment. The probabilistic analysis revealed that both aspect parameters play a crucial role in fiber reinforced soils. Further, it is concluded that the target reliability approach (TRA) gives a valuable insight with regards to choosing optimum aspect parameters for effective soil stabilization practice.