Impact des effluents de déchets miniers sur la résistance au cisaillement des sols latéritiques compactés utilisés dans les digues de confinement des rejets (RD Congo)/Impact of mining waste effluents on the shear strength of compacted lateritic soils used in waste containment dikes (DR Congo)

In most cases of failure of dikes, hydraulic fracturing is the evoked main cause. Severalauthors analyzed the properties of soils under mechanic and hydric solicitation. However, these analyses do nottake into account the chemical influence of the liquid percolating the matrix of soil. This article analyzes theimpact of the liquid effluents emanating from ore concentrators on the behavior of compacted lateritic soils inwaste containment dikes. It emphasizes the shear strengthparameters of the compacted latérites andpercolated by liquid effluents with different chemical nature. Demineralized water was taken as prototype. The tests include the shear strength measures consolidated drained and undrainedwhen thespecimens were imbibed with the different fluids. The results show that acid and basic liquid effluents affect the shear strength parameters and the strainmodulesareappreciably modified. The effect of the initial suctions and the density before the imbibition was alsoinvestigated, what reveals that the fall of shear strength parameters of lateritic soils, on wetting path (during the passage of the state partially saturated in the saturated state), is all the rougher as the moisture content of implementation during compaction is widely lower than the optimum water content. However, structural changes caused by initialsaturation and density of specimens seem to be more important for explaining the volumetric and deviator behaviorthan chemical interaction