<p>An important concern when using site-available marginal soils as backfill is their tendency to accumulate moisture due to low hydraulic conductivity, which leads to reduced strength and cause serviceability issues. This problem can be mitigated by reinforcing the above soils with geocomposites, which serve a dual function of structural reinforcement and drainage improvement. In this study, large direct shear box tests were conducted to determine the interface shear strength between geocomposites and marginal soils under varying density, normal stress, deformation rate, and moisture content. Each variable affected the amount of water migrating toward the geocomposite strips during shearing. The migrated water was maximum in soils compacted at optimum moisture content (OMC). Water migration was the least in samples compacted on the dry of OMC. The moisture also affected the interface friction efficiency, as it was found to increase with the increase in the sample’s initial moisture content. The friction efficiency reached a transient peak when the sample was compacted at OMC. It was also affected by the deformation rate. Interface friction ratio increased with the increase in dry density and the use of large size particles in the samples.</p>