Evaluation of the mechanical properties and critical slope parameters of mine tailings at Enyigba, South eastern, Nigeria

Abstract

This study examines the effects of slope geometry and Geo-mechanical parameters of tailing dumps at Enyigba mine, Nigeria. Fifty-two slopes were studied, with seven sampled for laboratory analysis. Correlation matrix and principal component analysis were employed in the data interpretations. The mechanical properties of the slope materials were investigated using geotechnical tests such as sieve analysis, Atterberg limits, compaction and undrained triaxial tests. Shear strength parameters generated from the triaxial tests were utilized in slope stability analysis executed with the Slope/W Geostudio software. Both statistical and slope stability methods suggested a combination of height and width (dimensions) has more significance on the stability of the dump slopes at Enyigba mine than slope angles (inclination). Height and width constituted 83.61% of the total variance data and represented 16.39%. Particle size distribution of the slope materials showed high percentage of fines. The computed factor of safety of the slopes ranged from 1.00 to 1.30, implying critical stability which indicates liability of the slopes to failure when predisposed to landslide triggering agents. Therefore, slope dimension optimization and stabilization are required on the tailing dumps at Enyigba to prevent severe landslide occurrence.