An assessment of the mechanical performance of a novel sand bentonite-glass fiber composite for the avoidance of catastrophic landfill failure

Abstract

• Octahedral shear stress increased higher at the fiber aspect ratio than at the fiber dosage. • At peak and residual stress, bearing capacity factors improved significantly. • Negative excess pore waster pressure increased with an aspect ratio of 40. • Energy absorption capacity was the function of fiber dosage and fiber aspect ratio. Compacted sand bentonite (CSB) blend is one of the finest materials for landfill construction. CSB mixes with a strain-softening tendency may fail abruptly, increasing soil permeability. Water movement over the shear zone can induce flow slides, triggering a catastrophic collapse. Waste glass fiber was added to the CSB mixture (90:10) in various fractions (0.5 %, 1, and 1.5 %) and aspect ratios (l/d = 40, 80, and 120) to prevent the soil structure from collapsing. A full-scale consolidated undrained (CU) test was conducted to assess (i.e., c-phi-analysis) the load-carrying capabilities of waste fiber soil composite. The octahedral shear stress was increased significantly for both stress level (i.e., peak and residual stress). Positive pore water pressure (PWP) increased progressively after initial yield, while negative PWP reduced as the aspect ratio increased from 80 to 120. Fiber dosage and fiber aspect ratio improved bearing capacity factors (N c ,N q ,N ϒ ) and undrained bearing capacity. The EAC (Energy absorption capacity) was determined using a numerical integration approach through MATLAB (version14), and the use of waste fiber resulted in a considerable improvement. Several variables contributed to the principal stress and soil modulus. Accordingly, they were framed with all the variables and built a model that matched the experimental results well.