Optimization of Sand-Bentonite Mixture for the Stable Engineered Barriers using Desirability Optimization Methodology: A Macro-Micro-Evaluation

In this paper, Desirability Optimization Methodology (DOM) is employed to achieve optimum sand bentonite mixture (SBM) based on multiple antagonist macro-geotechnical responses of the compacted SBM prepared using poorly graded with mean grain size around 0.2 mm and plasticity index 157% for stable engineered barriers (EBs). For purpose, varying mix designs at compaction energy 2,700 kN-m/m3 are initially tested determine their mechanical properties, volumetric-change behavior, hydraulic conductivity. The unconfined compressive strength, cohesion, angle internal fiction, swell pressure, compression index, conductivity taken as geotechnical design parameters SBM. Mathematical models developed statistically validated these content (SC) (BC) predictors. addition, also predict curves SBMs. Moreover, microstructural evaluation conducted through scanning electron microscope (SEM) analysis having a desirable microstructure EB. It observed that major shift in from medium pores micro-pores occurs BC between 20% 30%. Afterward, optimization carried out by integrating desirability function (D) algorithm, which subsequently simulated setting maximization strength minimization compressibility goals. A reasonably high D-value achieved SBMs SC:BC range 74:26 78:22 highest 75.63:24.37 against set This study manifests an effective pragmatic strategy designing EB considering its hydraulic, volumetric change, responses.